diff --git a/Source/Euonia.Core/Extensions/Extensions.Collection.cs b/Source/Euonia.Core/Extensions/Extensions.Collection.cs
index f5e21c1..317c05c 100644
--- a/Source/Euonia.Core/Extensions/Extensions.Collection.cs
+++ b/Source/Euonia.Core/Extensions/Extensions.Collection.cs
@@ -5,1078 +5,1072 @@
 
 public static partial class Extensions
 {
-    private static readonly Random _random = new();
-
-    /// <summary>
-    /// Performs the specified action on each element of the <see cref="IEnumerable{T}"/>
-    /// </summary>
-    /// <typeparam name="T">The type of the element.</typeparam>
-    /// <param name="source">The source.</param>
-    /// <param name="action">The System.Action`1 delegate to perform on each element of the <see cref="IEnumerable{T}"/>.</param>
-    /// <exception cref="NullReferenceException">Throws if <paramref name="source"/> is null.</exception>
-    /// <exception cref="ArgumentNullException">Throws if action is null.</exception>
-    public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        if (action == null)
-        {
-            throw new ArgumentNullException(nameof(action));
-        }
-
-        foreach (var value in source)
-        {
-            action(value);
-        }
-    }
-
-    /// <summary>
-    /// Determines whether the collection contains the object.
-    /// </summary>
-    /// <param name="source">The source.</param>
-    /// <param name="value">The value.</param>
-    /// <param name="comparison">The comparison.</param>
-    /// <returns><c>true</c> if [contains] [the specified value]; otherwise, <c>false</c>.</returns>
-    /// <exception cref="NullReferenceException"></exception>
-    public static bool Contains(this IEnumerable<string> source, string value, StringComparison comparison)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return source.Any(t => t.Equals(value, comparison));
-    }
-
-    /// <summary>
-    /// Determines whether the specified collection [is null or empty].
-    /// </summary>
-    /// <param name="source">The source.</param>
-    /// <returns><c>true</c> if the specified source [is null or empty]; otherwise, <c>false</c>.</returns>
-    public static bool IsNullOrEmpty(this IEnumerable source)
-    {
-        if (source == null)
-        {
-            return true;
-        }
-
-        return !source.GetEnumerator().MoveNext();
-    }
-
-    /// <summary>
-    /// Determines whether a sequence is null or empty.
-    /// </summary>
-    /// <typeparam name="T"></typeparam>
-    /// <param name="source">A sequence in which to locate a value.</param>
-    /// <returns></returns>
-    public static bool IsNullOrEmpty<T>(this IEnumerable<T> source)
-    {
-        return source == null || !source.Any();
-    }
-
-    /// <summary>
-    /// Determine whether the specified collection is equals to another.
-    /// </summary>
-    /// <typeparam name="T">The type of the collection item.</typeparam>
-    /// <param name="source">The source.</param>
-    /// <param name="dest">The dest.</param>
-    /// <returns><c>true</c> if collection is equals to another, <c>false</c> otherwise.</returns>
-    /// <exception cref="NullReferenceException"></exception>
-    /// <exception cref="ArgumentNullException">dest</exception>
-    public static bool Equals<T>(this IEnumerable<T> source, IEnumerable<T> dest) where T : IComparable
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        if (dest == null)
-        {
-            throw new ArgumentNullException(nameof(dest));
-        }
-
-        return dest.Count() == source.Count() && source.All(dest.Contains);
-    }
-
-    /// <summary>
-    /// Concatenates the elements of an object array, using the specified separator between each element.
-    /// </summary>
-    /// <typeparam name="T">Member type.</typeparam>
-    /// <param name="values">A collection that contains the objects to concatenate.</param>
-    /// <param name="separator"></param>
-    /// <returns></returns>
-    public static string Join<T>(this IEnumerable<T> values, string separator)
-    {
-        if (values == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return string.Join(separator, values);
-    }
-
-    /// <summary>
-    /// Concatenates the members of a collection, using the specified separator between each member.
-    /// </summary>
-    /// <typeparam name="T">Member type.</typeparam>
-    /// <param name="values">A collection that contains the objects to concatenate.</param>
-    /// <param name="separator">The string to use as a separator.separator is included in the returned string only if values has more than one element.</param>
-    /// <param name="startIndex"></param>
-    /// <param name="count"></param>
-    /// <returns></returns>
-    public static string Join<T>(this IEnumerable<T> values, string separator, int startIndex, int count)
-    {
-        if (values == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        if (startIndex >= values.Count())
-        {
-            throw new IndexOutOfRangeException();
-        }
-
-        return values.Skip(startIndex).Take(count).Join(separator);
-    }
-
-    /// <summary>
-    /// Convert Pageable collection to view collection.
-    /// </summary>
-    /// <typeparam name="T"></typeparam>
-    /// <param name="source"></param>
-    /// <returns></returns>
-    public static ViewCollection<T> ToView<T>(this PageableCollection<T> source) where T : class, new()
-    {
-        if (source == null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
-        return new ViewCollection<T>(source.ToArray(), source.TotalCount);
-    }
-
-    /// <summary>
-    /// Read <see cref="IList{T}"/> to a pageable collection.
-    /// </summary>
-    /// <typeparam name="T">The type of the element.</typeparam>
-    /// <param name="source">The source.</param>
-    /// <param name="totalCount">The total count.</param>
-    /// <param name="index">The index.</param>
-    /// <param name="size">The size.</param>
-    /// <returns>A new pageable collection contains all elements of <paramref name="source"/>.</returns>
-    /// <exception cref="NullReferenceException">Throws if source is null.</exception>
-    public static PageableCollection<T> Paginate<T>(this IList<T> source, long totalCount, int index, int size)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return new PageableCollection<T>(source) { TotalCount = totalCount, PageNumber = index, PageSize = size };
-    }
-
-    /// <summary>
-    /// Converts an exists pageable collection to another.
-    /// </summary>
-    /// <typeparam name="T">The type of collection items.</typeparam>
-    /// <param name="source">The source.</param>
-    /// <param name="index">The index.</param>
-    /// <param name="size">The size.</param>
-    /// <returns>A new pageable collection.</returns>
-    /// <exception cref="ArgumentNullException">Throw if source is null.</exception>
-    public static PageableCollection<T> Convert<T>(this PageableCollection<T> source, int index, int size)
-    {
-        if (source == null)
-        {
-            throw new ArgumentNullException(nameof(source));
-        }
-
-        return new PageableCollection<T>(source) { TotalCount = source.TotalCount, PageNumber = index, PageSize = size };
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="enumerable"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> enumerable)
-    {
-        var buffer = enumerable.ToList();
-
-        for (var i = 0; i < buffer.Count; i++)
-        {
-            var j = _random.Next(i, buffer.Count);
-
-            yield return buffer[j];
-
-            buffer[j] = buffer[i];
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    public static ObservableCollection<T> ToObservable<T>(this IEnumerable<T> source)
-    {
-        var collection = new ObservableCollection<T>(source);
-        return collection;
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    /// <exception cref="ArgumentNullException"></exception>
-    public static IReadOnlyCollection<T> Reify<T>(this IEnumerable<T> source)
-    {
-        return source switch
-        {
-            null => throw new ArgumentNullException(nameof(source)),
-            IReadOnlyCollection<T> result => result,
-            ICollection<T> collection => new CollectionWrapper<T>(collection),
-            ICollection nonGenericCollection => new NonGenericCollectionWrapper<T>(nonGenericCollection),
-            _ => new List<T>(source)
-        };
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="index"></param>
-    /// <param name="items"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void InsertRange<T>(this IList<T> source, int index, IEnumerable<T> items)
-    {
-        foreach (var item in items)
-        {
-            source.Insert(index++, item);
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    public static int FindIndex<T>(this IList<T> source, Predicate<T> selector)
-    {
-        for (var i = 0; i < source.Count; ++i)
-        {
-            if (selector(source[i]))
-            {
-                return i;
-            }
-        }
-
-        return -1;
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void AddFirst<T>(this IList<T> source, T item)
-    {
-        source.Insert(0, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void AddLast<T>(this IList<T> source, T item)
-    {
-        source.Insert(source.Count, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="existingItem"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void InsertAfter<T>(this IList<T> source, T existingItem, T item)
-    {
-        var index = source.IndexOf(existingItem);
-        if (index < 0)
-        {
-            source.AddFirst(item);
-            return;
-        }
-
-        source.Insert(index + 1, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void InsertAfter<T>(this IList<T> source, Predicate<T> selector, T item)
-    {
-        var index = source.FindIndex(selector);
-        if (index < 0)
-        {
-            source.AddFirst(item);
-            return;
-        }
-
-        source.Insert(index + 1, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="existingItem"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void InsertBefore<T>(this IList<T> source, T existingItem, T item)
-    {
-        var index = source.IndexOf(existingItem);
-        if (index < 0)
-        {
-            source.AddLast(item);
-            return;
-        }
-
-        source.Insert(index, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void InsertBefore<T>(this IList<T> source, Predicate<T> selector, T item)
-    {
-        var index = source.FindIndex(selector);
-        if (index < 0)
-        {
-            source.AddLast(item);
-            return;
-        }
-
-        source.Insert(index, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void ReplaceWhile<T>(this IList<T> source, Predicate<T> selector, T item)
-    {
-        for (var i = 0; i < source.Count; i++)
-        {
-            if (selector(source[i]))
-            {
-                source[i] = item;
-            }
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="itemFactory"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void ReplaceWhile<T>(this IList<T> source, Predicate<T> selector, Func<T, T> itemFactory)
-    {
-        for (var i = 0; i < source.Count; i++)
-        {
-            var item = source[i];
-            if (selector(item))
-            {
-                source[i] = itemFactory(item);
-            }
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void ReplaceOne<T>(this IList<T> source, Predicate<T> selector, T item)
-    {
-        for (var i = 0; i < source.Count; i++)
-        {
-            if (selector(source[i]))
-            {
-                source[i] = item;
-                return;
-            }
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="itemFactory"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void ReplaceOne<T>(this IList<T> source, Predicate<T> selector, Func<T, T> itemFactory)
-    {
-        for (var i = 0; i < source.Count; i++)
-        {
-            var item = source[i];
-            if (!selector(item))
-            {
-                continue;
-            }
-
-            source[i] = itemFactory(item);
-            return;
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="item"></param>
-    /// <param name="replaceWith"></param>
-    /// <typeparam name="T"></typeparam>
-    public static void ReplaceOne<T>(this IList<T> source, T item, T replaceWith)
-    {
-        for (var i = 0; i < source.Count; i++)
-        {
-            if (Comparer<T>.Default.Compare(source[i], item) != 0)
-            {
-                continue;
-            }
-
-            source[i] = replaceWith;
-            return;
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="targetIndex"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <exception cref="IndexOutOfRangeException"></exception>
-    public static void MoveItem<T>(this List<T> source, Predicate<T> selector, int targetIndex)
-    {
-        if (!targetIndex.IsBetween(0, source.Count - 1))
-        {
-            throw new IndexOutOfRangeException("targetIndex should be between 0 and " + (source.Count - 1));
-        }
-
-        var currentIndex = source.FindIndex(0, selector);
-        if (currentIndex == targetIndex)
-        {
-            return;
-        }
-
-        var item = source[currentIndex];
-        source.RemoveAt(currentIndex);
-        source.Insert(targetIndex, item);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="selector"></param>
-    /// <param name="factory"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    public static T GetOrAdd<T>([NotNull] this IList<T> source, Func<T, bool> selector, Func<T> factory)
-    {
-        Check.EnsureNotNull(source, nameof(source));
-
-        var item = source.FirstOrDefault(selector);
-
-        if (item == null)
-        {
-            item = factory();
-            source.Add(item);
-        }
-
-        return item;
-    }
-
-    /// <summary>
-    /// Sort a list by a topological sorting, which consider their dependencies.
-    /// </summary>
-    /// <typeparam name="T">The type of the members of values.</typeparam>
-    /// <param name="source">A list of objects to sort</param>
-    /// <param name="getDependencies">Function to resolve the dependencies</param>
-    /// <param name="comparer">Equality comparer for dependencies </param>
-    /// <returns>
-    /// Returns a new list ordered by dependencies.
-    /// If A depends on B, then B will come before than A in the resulting list.
-    /// </returns>
-    public static List<T> SortByDependencies<T>(
-        this IEnumerable<T> source,
-        Func<T, IEnumerable<T>> getDependencies,
-        IEqualityComparer<T> comparer = null)
-    {
-        /* See: http://www.codeproject.com/Articles/869059/Topological-sorting-in-Csharp
-         *      http://en.wikipedia.org/wiki/Topological_sorting
-         */
-
-        var sorted = new List<T>();
-        var visited = new Dictionary<T, bool>(comparer);
-
-        foreach (var item in source)
-        {
-            SortByDependenciesVisit(item, getDependencies, sorted, visited);
-        }
-
-        return sorted;
-    }
-
-    /// <summary>
-    ///
-    /// </summary>
-    /// <typeparam name="T">The type of the members of values.</typeparam>
-    /// <param name="item">Item to resolve</param>
-    /// <param name="getDependencies">Function to resolve the dependencies</param>
-    /// <param name="sorted">List with the sorted items</param>
-    /// <param name="visited">Dictionary with the visited items</param>
-    private static void SortByDependenciesVisit<T>(T item, Func<T, IEnumerable<T>> getDependencies, IList<T> sorted, Dictionary<T, bool> visited)
-    {
-        var alreadyVisited = visited.TryGetValue(item, out var inProcess);
-
-        if (alreadyVisited)
-        {
-            if (inProcess)
-            {
-                throw new ArgumentException("Cyclic dependency found! Item: " + item);
-            }
-        }
-        else
-        {
-            visited[item] = true;
-
-            var dependencies = getDependencies(item);
-            if (dependencies != null)
-            {
-                foreach (var dependency in dependencies)
-                {
-                    SortByDependenciesVisit(dependency, getDependencies, sorted, visited);
-                }
-            }
-
-            visited[item] = false;
-            sorted.Add(item);
-        }
-    }
-
-    /// <summary>
-    /// Concatenates the members of a constructed <see cref="IEnumerable{T}"/> collection of type System.String, using the specified separator between each member.
-    /// This is a shortcut for string.Join(...)
-    /// </summary>
-    /// <param name="source">A collection that contains the strings to concatenate.</param>
-    /// <param name="separator">The string to use as a separator. separator is included in the returned string only if values has more than one element.</param>
-    /// <returns>A string that consists of the members of values delimited by the separator string. If values has no members, the method returns System.String.Empty.</returns>
-    public static string JoinAsString(this IEnumerable<string> source, string separator)
-    {
-        return string.Join(separator, source);
-    }
-
-    /// <summary>
-    /// Concatenates the members of a collection, using the specified separator between each member.
-    /// This is a shortcut for string.Join(...)
-    /// </summary>
-    /// <param name="source">A collection that contains the objects to concatenate.</param>
-    /// <param name="separator">The string to use as a separator. separator is included in the returned string only if values has more than one element.</param>
-    /// <typeparam name="T">The type of the members of values.</typeparam>
-    /// <returns>A string that consists of the members of values delimited by the separator string. If values has no members, the method returns System.String.Empty.</returns>
-    public static string JoinAsString<T>(this IEnumerable<T> source, string separator)
-    {
-        return string.Join(separator, source);
-    }
-
-    /// <summary>
-    /// Filters a <see cref="IEnumerable{T}"/> by given predicate if given condition is true.
-    /// </summary>
-    /// <param name="source">Enumerable to apply filtering</param>
-    /// <param name="condition">A boolean value</param>
-    /// <param name="predicate">Predicate to filter the enumerable</param>
-    /// <returns>Filtered or not filtered enumerable based on <paramref name="condition"/></returns>
-    public static IEnumerable<T> WhereIf<T>(this IEnumerable<T> source, bool condition, Func<T, bool> predicate)
-    {
-        return condition
-            ? source.Where(predicate)
-            : source;
-    }
-
-    /// <summary>
-    /// Filters a <see cref="IEnumerable{T}"/> by given predicate if given condition is true.
-    /// </summary>
-    /// <param name="source">Enumerable to apply filtering</param>
-    /// <param name="condition">A boolean value</param>
-    /// <param name="predicate">Predicate to filter the enumerable</param>
-    /// <returns>Filtered or not filtered enumerable based on <paramref name="condition"/></returns>
-    public static IEnumerable<T> WhereIf<T>(this IEnumerable<T> source, bool condition, Func<T, int, bool> predicate)
-    {
-        return condition
-            ? source.Where(predicate)
-            : source;
-    }
-
-    /// <summary>
-    /// This method is used to try to get a value in a dictionary if it does exists.
-    /// </summary>
-    /// <typeparam name="T">Type of the value</typeparam>
-    /// <param name="dictionary">The collection object</param>
-    /// <param name="key">Key</param>
-    /// <param name="value">Value of the key (or default value if key not exists)</param>
-    /// <returns>True if key does exists in the dictionary</returns>
-    internal static bool TryGetValue<T>(this IDictionary<string, object> dictionary, string key, out T value)
-    {
-        if (dictionary.TryGetValue(key, out var valueObj) && valueObj is T result)
-        {
-            value = result;
-            return true;
-        }
-
-        value = default;
-        return false;
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrDefault<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key)
-    {
-        return dictionary.TryGetValue(key, out var obj) ? obj : default;
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
-    {
-        return dictionary.TryGetValue(key, out var obj) ? obj : default;
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrDefault<TKey, TValue>(this IReadOnlyDictionary<TKey, TValue> dictionary, TKey key)
-    {
-        return dictionary.TryGetValue(key, out var obj) ? obj : default;
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrDefault<TKey, TValue>(this ConcurrentDictionary<TKey, TValue> dictionary, TKey key)
-    {
-        return dictionary.TryGetValue(key, out var obj) ? obj : default;
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TValue> factory)
-    {
-        if (dictionary.TryGetValue(key, out var obj))
-        {
-            return obj;
-        }
-
-        return dictionary[key] = factory(key);
-    }
-
-    /// <summary>
-    /// Gets a value from the dictionary with given key. Returns default value if can not find.
-    /// </summary>
-    /// <param name="dictionary">Dictionary to check and get</param>
-    /// <param name="key">Key to find the value</param>
-    /// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
-    /// <typeparam name="TKey">Type of the key</typeparam>
-    /// <typeparam name="TValue">Type of the value</typeparam>
-    /// <returns>Value if found, default if can not found.</returns>
-    public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TValue> factory)
-    {
-        return dictionary.GetOrAdd(key, _ => factory());
-    }
-
-    /// <summary>
-    /// Adds an item to the collection if it's not already in the collection.
-    /// </summary>
-    /// <param name="source">The collection</param>
-    /// <param name="item">Item to check and add</param>
-    /// <typeparam name="T">Type of the items in the collection</typeparam>
-    /// <returns>Returns True if added, returns False if not.</returns>
-    public static bool AddIfNotContains<T>([NotNull] this ICollection<T> source, T item)
-    {
-        Check.EnsureNotNull(source, nameof(source));
-
-        if (source.Contains(item))
-        {
-            return false;
-        }
-
-        source.Add(item);
-        return true;
-    }
-
-    /// <summary>
-    /// Adds items to the collection which are not already in the collection.
-    /// </summary>
-    /// <param name="source">The collection</param>
-    /// <param name="items">Item to check and add</param>
-    /// <typeparam name="T">Type of the items in the collection</typeparam>
-    /// <returns>Returns the added items.</returns>
-    public static IEnumerable<T> AddIfNotContains<T>([NotNull] this ICollection<T> source, IEnumerable<T> items)
-    {
-        Check.EnsureNotNull(source, nameof(source));
-
-        var addedItems = new List<T>();
-
-        foreach (var item in items)
-        {
-            if (source.Contains(item))
-            {
-                continue;
-            }
-
-            source.Add(item);
-            addedItems.Add(item);
-        }
-
-        return addedItems;
-    }
-
-    /// <summary>
-    /// Adds an item to the collection if it's not already in the collection based on the given <paramref name="predicate"/>.
-    /// </summary>
-    /// <param name="source">The collection</param>
-    /// <param name="predicate">The condition to decide if the item is already in the collection</param>
-    /// <param name="itemFactory">A factory that returns the item</param>
-    /// <typeparam name="T">Type of the items in the collection</typeparam>
-    /// <returns>Returns True if added, returns False if not.</returns>
-    public static bool AddIfNotContains<T>([NotNull] this ICollection<T> source, [NotNull] Func<T, bool> predicate, [NotNull] Func<T> itemFactory)
-    {
-        Check.EnsureNotNull(source, nameof(source));
-        Check.EnsureNotNull(predicate, nameof(predicate));
-        Check.EnsureNotNull(itemFactory, nameof(itemFactory));
-
-        if (source.Any(predicate))
-        {
-            return false;
-        }
-
-        source.Add(itemFactory());
-        return true;
-    }
-
-    /// <summary>
-    /// Removes all items from the collection those satisfy the given <paramref name="predicate"/>.
-    /// </summary>
-    /// <typeparam name="T">Type of the items in the collection</typeparam>
-    /// <param name="source">The collection</param>
-    /// <param name="predicate">The condition to remove the items</param>
-    /// <returns>List of removed items</returns>
-    public static IList<T> RemoveAll<T>([NotNull] this ICollection<T> source, Func<T, bool> predicate)
-    {
-        var items = source.Where(predicate).ToList();
-
-        foreach (var item in items)
-        {
-            source.Remove(item);
-        }
-
-        return items;
-    }
-
-    /// <summary>
-    /// Removes all items from the collection those satisfy the given <paramref>
-    ///     <name>predicate</name>
-    /// </paramref>
-    /// .
-    /// </summary>
-    /// <typeparam name="T">Type of the items in the collection</typeparam>
-    /// <param name="source">The collection</param>
-    /// <param name="items">Items to be removed from the list</param>
-    public static void RemoveAll<T>([NotNull] this ICollection<T> source, IEnumerable<T> items)
-    {
-        foreach (var item in items)
-        {
-            source.Remove(item);
-        }
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="dictionary"></param>
-    /// <param name="key"></param>
-    /// <param name="value"></param>
-    /// <typeparam name="TKey"></typeparam>
-    /// <typeparam name="TValue"></typeparam>
-    /// <returns></returns>
-    public static IDictionary<TKey, TValue> Set<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue value)
-    {
-        dictionary[key] = value;
-        return dictionary;
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="dictionary"></param>
-    /// <param name="key"></param>
-    /// <param name="func"></param>
-    /// <typeparam name="TKey"></typeparam>
-    /// <typeparam name="TValue"></typeparam>
-    /// <typeparam name="TRef"></typeparam>
-    public static void TryGetValue<TKey, TValue, TRef>(this IDictionary<TKey, TValue> dictionary, TKey key, Action<TRef> func)
-    {
-        if (!dictionary.TryGetValue(key, out var value))
-        {
-            return;
-        }
-
-        var refValue = (TRef)System.Convert.ChangeType(value, typeof(TRef));
-        func(refValue);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="dictionary"></param>
-    /// <param name="key"></param>
-    /// <param name="func"></param>
-    /// <typeparam name="TKey"></typeparam>
-    /// <typeparam name="TRef"></typeparam>
-    public static void TryGetValue<TKey, TRef>(this IDictionary<TKey, object> dictionary, TKey key, Action<TRef> func)
-    {
-        if (!dictionary.TryGetValue(key, out var value))
-        {
-            return;
-        }
-
-        var refValue = (TRef)value;
-        func(refValue);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="dictionary"></param>
-    /// <param name="key"></param>
-    /// <param name="func"></param>
-    /// <typeparam name="TKey"></typeparam>
-    /// <typeparam name="TValue"></typeparam>
-    public static void TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Action<TValue> func)
-    {
-        if (!dictionary.TryGetValue(key, out var value))
-        {
-            return;
-        }
-
-        func(value);
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="dictionary"></param>
-    /// <param name="key"></param>
-    /// <param name="comparison"></param>
-    /// <typeparam name="TValue"></typeparam>
-    /// <returns></returns>
-    public static TValue GetValue<TValue>(this IDictionary<string, TValue> dictionary, string key, StringComparison comparison)
-    {
-        var item = dictionary.FirstOrDefault(t => t.Key.Equals(key, comparison));
-        return item.Value;
-    }
-
-    /// <summary>
-    /// Try get value for specified key from dictionary.
-    /// </summary>
-    /// <typeparam name="TKey">The key type.</typeparam>
-    /// <typeparam name="TValue">The value type.</typeparam>
-    /// <param name="source"></param>
-    /// <param name="key"></param>
-    /// <returns></returns>
-    public static TValue TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return source.TryGetValue(key, out var value) ? value : default;
-    }
-
-    /// <summary>
-    /// Try get value for specified key from dictionary.
-    /// </summary>
-    /// <typeparam name="TKey">The key type.</typeparam>
-    /// <typeparam name="TValue">The value type.</typeparam>
-    /// <param name="source"></param>
-    /// <param name="key"></param>
-    /// <param name="defaultValue">The defaut value if key doesn't exists.</param>
-    /// <returns></returns>
-    /// <exception cref="NullReferenceException"></exception>
-    public static TValue TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key, TValue defaultValue)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return source.TryGetValue(key, out var value) ? value : defaultValue;
-    }
-
-    /// <summary>
-    /// Try get exists value for specified key or set value if not exists.
-    /// </summary>
-    /// <typeparam name="TKey">The type of the key.</typeparam>
-    /// <typeparam name="TValue">The type of the value.</typeparam>
-    /// <param name="source">The source.</param>
-    /// <param name="key">The key.</param>
-    /// <returns>The value.</returns>
-    /// <exception cref="NullReferenceException">Throws if <paramref name="source"/> is null.</exception>
-    public static TValue TryGetOrSetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        if (source.TryGetValue(key, out var value))
-        {
-            return value;
-        }
-
-        source.Add(key, value);
-        return source[key];
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="source"></param>
-    /// <param name="key"></param>
-    /// <param name="defaultValue"></param>
-    /// <param name="comparison"></param>
-    /// <typeparam name="TValue"></typeparam>
-    /// <returns></returns>
-    /// <exception cref="NullReferenceException"></exception>
-    public static TValue TryGetValue<TValue>(this IDictionary<string, TValue> source, string key, TValue defaultValue, StringComparison comparison)
-    {
-        if (source == null)
-        {
-            throw new NullReferenceException();
-        }
-
-        return source.Keys.Contains(key, comparison) ? source.FirstOrDefault(t => t.Key.Equals(key, comparison)).Value : defaultValue;
-    }
-
-    /// <summary>
-    /// Gets index of item.
-    /// </summary>
-    /// <param name="enumerable"></param>
-    /// <param name="item"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    /// <exception cref="ArgumentNullException"></exception>
-    public static int IndexOf<T>(this IEnumerable<T> enumerable, T item)
-    {
-        if (enumerable == null)
-            throw new ArgumentNullException(nameof(enumerable));
-
-        var i = 0;
-        foreach (var element in enumerable)
-        {
-            if (Equals(element, item))
-            {
-                return i;
-            }
-
-            i++;
-        }
-
-        return -1;
-    }
-
-    /// <summary>
-    /// Gets index of item which matches the predicate.
-    /// </summary>
-    /// <param name="enumerable"></param>
-    /// <param name="predicate"></param>
-    /// <typeparam name="T"></typeparam>
-    /// <returns></returns>
-    public static int IndexOf<T>(this IEnumerable<T> enumerable, Func<T, bool> predicate)
-    {
-        var i = 0;
-        foreach (var element in enumerable)
-        {
-            if (predicate(element))
-            {
-                return i;
-            }
-
-            i++;
-        }
-
-        return -1;
-    }
+	private static readonly Random _random = new();
+
+	/// <summary>
+	/// Performs the specified action on each element of the <see cref="IEnumerable{T}"/>
+	/// </summary>
+	/// <typeparam name="T">The type of the element.</typeparam>
+	/// <param name="source">The source.</param>
+	/// <param name="action">The System.Action`1 delegate to perform on each element of the <see cref="IEnumerable{T}"/>.</param>
+	/// <exception cref="NullReferenceException">Throws if <paramref name="source"/> is null.</exception>
+	/// <exception cref="ArgumentNullException">Throws if action is null.</exception>
+	public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		ArgumentAssert.ThrowIfNull(action, nameof(action));
+
+		foreach (var value in source)
+		{
+			action(value);
+		}
+	}
+
+	/// <summary>
+	/// Determines whether the collection contains the object.
+	/// </summary>
+	/// <param name="source">The source.</param>
+	/// <param name="value">The value.</param>
+	/// <param name="comparison">The comparison.</param>
+	/// <returns><c>true</c> if [contains] [the specified value]; otherwise, <c>false</c>.</returns>
+	/// <exception cref="NullReferenceException"></exception>
+	public static bool Contains(this IEnumerable<string> source, string value, StringComparison comparison)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return source.Any(t => t.Equals(value, comparison));
+	}
+
+	/// <summary>
+	/// Determines whether the specified collection [is null or empty].
+	/// </summary>
+	/// <param name="source">The source.</param>
+	/// <returns><c>true</c> if the specified source [is null or empty]; otherwise, <c>false</c>.</returns>
+	public static bool IsNullOrEmpty(this IEnumerable source)
+	{
+		if (source == null)
+		{
+			return true;
+		}
+
+		return !source.GetEnumerator().MoveNext();
+	}
+
+	/// <summary>
+	/// Determines whether a sequence is null or empty.
+	/// </summary>
+	/// <typeparam name="T"></typeparam>
+	/// <param name="source">A sequence in which to locate a value.</param>
+	/// <returns></returns>
+	public static bool IsNullOrEmpty<T>(this IEnumerable<T> source)
+	{
+		return source == null || !source.Any();
+	}
+
+	/// <summary>
+	/// Determine whether the specified collection is equals to another.
+	/// </summary>
+	/// <typeparam name="T">The type of the collection item.</typeparam>
+	/// <param name="source">The source.</param>
+	/// <param name="dest">The dest.</param>
+	/// <returns><c>true</c> if collection is equals to another, <c>false</c> otherwise.</returns>
+	/// <exception cref="NullReferenceException"></exception>
+	/// <exception cref="ArgumentNullException">dest</exception>
+	public static bool Equals<T>(this IEnumerable<T> source, IEnumerable<T> dest) where T : IComparable
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		ArgumentAssert.ThrowIfNull(dest, nameof(dest));
+
+		return dest.Count() == source.Count() && source.All(dest.Contains);
+	}
+
+	/// <summary>
+	/// Concatenates the elements of an object array, using the specified separator between each element.
+	/// </summary>
+	/// <typeparam name="T">Member type.</typeparam>
+	/// <param name="values">A collection that contains the objects to concatenate.</param>
+	/// <param name="separator"></param>
+	/// <returns></returns>
+	public static string Join<T>(this IEnumerable<T> values, string separator)
+	{
+		if (values == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return string.Join(separator, values);
+	}
+
+	/// <summary>
+	/// Concatenates the members of a collection, using the specified separator between each member.
+	/// </summary>
+	/// <typeparam name="T">Member type.</typeparam>
+	/// <param name="values">A collection that contains the objects to concatenate.</param>
+	/// <param name="separator">The string to use as a separator.separator is included in the returned string only if values has more than one element.</param>
+	/// <param name="startIndex"></param>
+	/// <param name="count"></param>
+	/// <returns></returns>
+	public static string Join<T>(this IEnumerable<T> values, string separator, int startIndex, int count)
+	{
+		if (values == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		if (startIndex >= values.Count())
+		{
+			throw new IndexOutOfRangeException();
+		}
+
+		return values.Skip(startIndex).Take(count).Join(separator);
+	}
+
+	/// <summary>
+	/// Convert Pageable collection to view collection.
+	/// </summary>
+	/// <typeparam name="T"></typeparam>
+	/// <param name="source"></param>
+	/// <returns></returns>
+	public static ViewCollection<T> ToView<T>(this PageableCollection<T> source) where T : class, new()
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return new ViewCollection<T>(source.ToArray(), source.TotalCount);
+	}
+
+	/// <summary>
+	/// Read <see cref="IList{T}"/> to a pageable collection.
+	/// </summary>
+	/// <typeparam name="T">The type of the element.</typeparam>
+	/// <param name="source">The source.</param>
+	/// <param name="totalCount">The total count.</param>
+	/// <param name="index">The index.</param>
+	/// <param name="size">The size.</param>
+	/// <returns>A new pageable collection contains all elements of <paramref name="source"/>.</returns>
+	/// <exception cref="NullReferenceException">Throws if source is null.</exception>
+	public static PageableCollection<T> Paginate<T>(this IList<T> source, long totalCount, int index, int size)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return new PageableCollection<T>(source) { TotalCount = totalCount, PageNumber = index, PageSize = size };
+	}
+
+	/// <summary>
+	/// Converts an exists pageable collection to another.
+	/// </summary>
+	/// <typeparam name="T">The type of collection items.</typeparam>
+	/// <param name="source">The source.</param>
+	/// <param name="index">The index.</param>
+	/// <param name="size">The size.</param>
+	/// <returns>A new pageable collection.</returns>
+	/// <exception cref="ArgumentNullException">Throw if source is null.</exception>
+	public static PageableCollection<T> Convert<T>(this PageableCollection<T> source, int index, int size)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException(nameof(source));
+		}
+
+		return new PageableCollection<T>(source) { TotalCount = source.TotalCount, PageNumber = index, PageSize = size };
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="enumerable"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> enumerable)
+	{
+		var buffer = enumerable.ToList();
+
+		for (var i = 0; i < buffer.Count; i++)
+		{
+			var j = _random.Next(i, buffer.Count);
+
+			yield return buffer[j];
+
+			buffer[j] = buffer[i];
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	public static ObservableCollection<T> ToObservable<T>(this IEnumerable<T> source)
+	{
+		var collection = new ObservableCollection<T>(source);
+		return collection;
+	}
+
+	/// <summary>
+	/// Reify the specified collection.
+	/// </summary>
+	/// <param name="source"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	/// <exception cref="ArgumentNullException"></exception>
+	public static IReadOnlyCollection<T> Reify<T>(this IEnumerable<T> source)
+	{
+		return source switch
+		{
+			null => throw new NullReferenceException(),
+			IReadOnlyCollection<T> result => result,
+			ICollection<T> collection => new CollectionWrapper<T>(collection),
+			ICollection nonGenericCollection => new NonGenericCollectionWrapper<T>(nonGenericCollection),
+			_ => new List<T>(source)
+		};
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="index"></param>
+	/// <param name="items"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void InsertRange<T>(this IList<T> source, int index, IEnumerable<T> items)
+	{
+		foreach (var item in items)
+		{
+			source.Insert(index++, item);
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	public static int FindIndex<T>(this IList<T> source, Predicate<T> selector)
+	{
+		for (var i = 0; i < source.Count; ++i)
+		{
+			if (selector(source[i]))
+			{
+				return i;
+			}
+		}
+
+		return -1;
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void AddFirst<T>(this IList<T> source, T item)
+	{
+		source.Insert(0, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void AddLast<T>(this IList<T> source, T item)
+	{
+		source.Insert(source.Count, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="existingItem"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void InsertAfter<T>(this IList<T> source, T existingItem, T item)
+	{
+		var index = source.IndexOf(existingItem);
+		if (index < 0)
+		{
+			source.AddFirst(item);
+			return;
+		}
+
+		source.Insert(index + 1, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void InsertAfter<T>(this IList<T> source, Predicate<T> selector, T item)
+	{
+		var index = source.FindIndex(selector);
+		if (index < 0)
+		{
+			source.AddFirst(item);
+			return;
+		}
+
+		source.Insert(index + 1, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="existingItem"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void InsertBefore<T>(this IList<T> source, T existingItem, T item)
+	{
+		var index = source.IndexOf(existingItem);
+		if (index < 0)
+		{
+			source.AddLast(item);
+			return;
+		}
+
+		source.Insert(index, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void InsertBefore<T>(this IList<T> source, Predicate<T> selector, T item)
+	{
+		var index = source.FindIndex(selector);
+		if (index < 0)
+		{
+			source.AddLast(item);
+			return;
+		}
+
+		source.Insert(index, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void ReplaceWhile<T>(this IList<T> source, Predicate<T> selector, T item)
+	{
+		for (var i = 0; i < source.Count; i++)
+		{
+			if (selector(source[i]))
+			{
+				source[i] = item;
+			}
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="itemFactory"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void ReplaceWhile<T>(this IList<T> source, Predicate<T> selector, Func<T, T> itemFactory)
+	{
+		for (var i = 0; i < source.Count; i++)
+		{
+			var item = source[i];
+			if (selector(item))
+			{
+				source[i] = itemFactory(item);
+			}
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void ReplaceOne<T>(this IList<T> source, Predicate<T> selector, T item)
+	{
+		for (var i = 0; i < source.Count; i++)
+		{
+			if (selector(source[i]))
+			{
+				source[i] = item;
+				return;
+			}
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="itemFactory"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void ReplaceOne<T>(this IList<T> source, Predicate<T> selector, Func<T, T> itemFactory)
+	{
+		for (var i = 0; i < source.Count; i++)
+		{
+			var item = source[i];
+			if (!selector(item))
+			{
+				continue;
+			}
+
+			source[i] = itemFactory(item);
+			return;
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="item"></param>
+	/// <param name="replaceWith"></param>
+	/// <typeparam name="T"></typeparam>
+	public static void ReplaceOne<T>(this IList<T> source, T item, T replaceWith)
+	{
+		for (var i = 0; i < source.Count; i++)
+		{
+			if (Comparer<T>.Default.Compare(source[i], item) != 0)
+			{
+				continue;
+			}
+
+			source[i] = replaceWith;
+			return;
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="targetIndex"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <exception cref="IndexOutOfRangeException"></exception>
+	public static void MoveItem<T>(this List<T> source, Predicate<T> selector, int targetIndex)
+	{
+		if (!targetIndex.IsBetween(0, source.Count - 1))
+		{
+			throw new IndexOutOfRangeException("targetIndex should be between 0 and " + (source.Count - 1));
+		}
+
+		var currentIndex = source.FindIndex(0, selector);
+		if (currentIndex == targetIndex)
+		{
+			return;
+		}
+
+		var item = source[currentIndex];
+		source.RemoveAt(currentIndex);
+		source.Insert(targetIndex, item);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="selector"></param>
+	/// <param name="factory"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	public static T GetOrAdd<T>([NotNull] this IList<T> source, Func<T, bool> selector, Func<T> factory)
+	{
+		Check.EnsureNotNull(source, nameof(source));
+
+		var item = source.FirstOrDefault(selector);
+
+		if (item == null)
+		{
+			item = factory();
+			source.Add(item);
+		}
+
+		return item;
+	}
+
+	/// <summary>
+	/// Sort a list by a topological sorting, which consider their dependencies.
+	/// </summary>
+	/// <typeparam name="T">The type of the members of values.</typeparam>
+	/// <param name="source">A list of objects to sort</param>
+	/// <param name="getDependencies">Function to resolve the dependencies</param>
+	/// <param name="comparer">Equality comparer for dependencies </param>
+	/// <returns>
+	/// Returns a new list ordered by dependencies.
+	/// If A depends on B, then B will come before than A in the resulting list.
+	/// </returns>
+	public static List<T> SortByDependencies<T>(
+		this IEnumerable<T> source,
+		Func<T, IEnumerable<T>> getDependencies,
+		IEqualityComparer<T> comparer = null)
+	{
+		/* See: http://www.codeproject.com/Articles/869059/Topological-sorting-in-Csharp
+		 *      http://en.wikipedia.org/wiki/Topological_sorting
+		 */
+
+		var sorted = new List<T>();
+		var visited = new Dictionary<T, bool>(comparer);
+
+		foreach (var item in source)
+		{
+			SortByDependenciesVisit(item, getDependencies, sorted, visited);
+		}
+
+		return sorted;
+	}
+
+	/// <summary>
+	///
+	/// </summary>
+	/// <typeparam name="T">The type of the members of values.</typeparam>
+	/// <param name="item">Item to resolve</param>
+	/// <param name="getDependencies">Function to resolve the dependencies</param>
+	/// <param name="sorted">List with the sorted items</param>
+	/// <param name="visited">Dictionary with the visited items</param>
+	private static void SortByDependenciesVisit<T>(T item, Func<T, IEnumerable<T>> getDependencies, IList<T> sorted, Dictionary<T, bool> visited)
+	{
+		var alreadyVisited = visited.TryGetValue(item, out var inProcess);
+
+		if (alreadyVisited)
+		{
+			if (inProcess)
+			{
+				throw new ArgumentException("Cyclic dependency found! Item: " + item);
+			}
+		}
+		else
+		{
+			visited[item] = true;
+
+			var dependencies = getDependencies(item);
+			if (dependencies != null)
+			{
+				foreach (var dependency in dependencies)
+				{
+					SortByDependenciesVisit(dependency, getDependencies, sorted, visited);
+				}
+			}
+
+			visited[item] = false;
+			sorted.Add(item);
+		}
+	}
+
+	/// <summary>
+	/// Concatenates the members of a constructed <see cref="IEnumerable{T}"/> collection of type System.String, using the specified separator between each member.
+	/// This is a shortcut for string.Join(...)
+	/// </summary>
+	/// <param name="source">A collection that contains the strings to concatenate.</param>
+	/// <param name="separator">The string to use as a separator. separator is included in the returned string only if values has more than one element.</param>
+	/// <returns>A string that consists of the members of values delimited by the separator string. If values has no members, the method returns System.String.Empty.</returns>
+	public static string JoinAsString(this IEnumerable<string> source, string separator)
+	{
+		return string.Join(separator, source);
+	}
+
+	/// <summary>
+	/// Concatenates the members of a collection, using the specified separator between each member.
+	/// This is a shortcut for string.Join(...)
+	/// </summary>
+	/// <param name="source">A collection that contains the objects to concatenate.</param>
+	/// <param name="separator">The string to use as a separator. separator is included in the returned string only if values has more than one element.</param>
+	/// <typeparam name="T">The type of the members of values.</typeparam>
+	/// <returns>A string that consists of the members of values delimited by the separator string. If values has no members, the method returns System.String.Empty.</returns>
+	public static string JoinAsString<T>(this IEnumerable<T> source, string separator)
+	{
+		return string.Join(separator, source);
+	}
+
+	/// <summary>
+	/// Filters a <see cref="IEnumerable{T}"/> by given predicate if given condition is true.
+	/// </summary>
+	/// <param name="source">Enumerable to apply filtering</param>
+	/// <param name="condition">A boolean value</param>
+	/// <param name="predicate">Predicate to filter the enumerable</param>
+	/// <returns>Filtered or not filtered enumerable based on <paramref name="condition"/></returns>
+	public static IEnumerable<T> WhereIf<T>(this IEnumerable<T> source, bool condition, Func<T, bool> predicate)
+	{
+		return condition
+			? source.Where(predicate)
+			: source;
+	}
+
+	/// <summary>
+	/// Filters a <see cref="IEnumerable{T}"/> by given predicate if given condition is true.
+	/// </summary>
+	/// <param name="source">Enumerable to apply filtering</param>
+	/// <param name="condition">A boolean value</param>
+	/// <param name="predicate">Predicate to filter the enumerable</param>
+	/// <returns>Filtered or not filtered enumerable based on <paramref name="condition"/></returns>
+	public static IEnumerable<T> WhereIf<T>(this IEnumerable<T> source, bool condition, Func<T, int, bool> predicate)
+	{
+		return condition
+			? source.Where(predicate)
+			: source;
+	}
+
+	/// <summary>
+	/// This method is used to try to get a value in a dictionary if it does exists.
+	/// </summary>
+	/// <typeparam name="T">Type of the value</typeparam>
+	/// <param name="dictionary">The collection object</param>
+	/// <param name="key">Key</param>
+	/// <param name="value">Value of the key (or default value if key not exists)</param>
+	/// <returns>True if key does exists in the dictionary</returns>
+	internal static bool TryGetValue<T>(this IDictionary<string, object> dictionary, string key, out T value)
+	{
+		if (dictionary.TryGetValue(key, out var valueObj) && valueObj is T result)
+		{
+			value = result;
+			return true;
+		}
+
+		value = default;
+		return false;
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrDefault<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key)
+	{
+		return dictionary.TryGetValue(key, out var obj) ? obj : default;
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
+	{
+		return dictionary.TryGetValue(key, out var obj) ? obj : default;
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrDefault<TKey, TValue>(this IReadOnlyDictionary<TKey, TValue> dictionary, TKey key)
+	{
+		return dictionary.TryGetValue(key, out var obj) ? obj : default;
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrDefault<TKey, TValue>(this ConcurrentDictionary<TKey, TValue> dictionary, TKey key)
+	{
+		return dictionary.TryGetValue(key, out var obj) ? obj : default;
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TValue> factory)
+	{
+		if (dictionary.TryGetValue(key, out var obj))
+		{
+			return obj;
+		}
+
+		return dictionary[key] = factory(key);
+	}
+
+	/// <summary>
+	/// Gets a value from the dictionary with given key. Returns default value if can not find.
+	/// </summary>
+	/// <param name="dictionary">Dictionary to check and get</param>
+	/// <param name="key">Key to find the value</param>
+	/// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
+	/// <typeparam name="TKey">Type of the key</typeparam>
+	/// <typeparam name="TValue">Type of the value</typeparam>
+	/// <returns>Value if found, default if can not found.</returns>
+	public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TValue> factory)
+	{
+		return dictionary.GetOrAdd(key, _ => factory());
+	}
+
+	/// <summary>
+	/// Adds an item to the collection if it's not already in the collection.
+	/// </summary>
+	/// <param name="source">The collection</param>
+	/// <param name="item">Item to check and add</param>
+	/// <typeparam name="T">Type of the items in the collection</typeparam>
+	/// <returns>Returns True if added, returns False if not.</returns>
+	public static bool AddIfNotContains<T>([NotNull] this ICollection<T> source, T item)
+	{
+		Check.EnsureNotNull(source, nameof(source));
+
+		if (source.Contains(item))
+		{
+			return false;
+		}
+
+		source.Add(item);
+		return true;
+	}
+
+	/// <summary>
+	/// Adds items to the collection which are not already in the collection.
+	/// </summary>
+	/// <param name="source">The collection</param>
+	/// <param name="items">Item to check and add</param>
+	/// <typeparam name="T">Type of the items in the collection</typeparam>
+	/// <returns>Returns the added items.</returns>
+	public static IEnumerable<T> AddIfNotContains<T>([NotNull] this ICollection<T> source, IEnumerable<T> items)
+	{
+		Check.EnsureNotNull(source, nameof(source));
+
+		var addedItems = new List<T>();
+
+		foreach (var item in items)
+		{
+			if (source.Contains(item))
+			{
+				continue;
+			}
+
+			source.Add(item);
+			addedItems.Add(item);
+		}
+
+		return addedItems;
+	}
+
+	/// <summary>
+	/// Adds an item to the collection if it's not already in the collection based on the given <paramref name="predicate"/>.
+	/// </summary>
+	/// <param name="source">The collection</param>
+	/// <param name="predicate">The condition to decide if the item is already in the collection</param>
+	/// <param name="itemFactory">A factory that returns the item</param>
+	/// <typeparam name="T">Type of the items in the collection</typeparam>
+	/// <returns>Returns True if added, returns False if not.</returns>
+	public static bool AddIfNotContains<T>([NotNull] this ICollection<T> source, [NotNull] Func<T, bool> predicate, [NotNull] Func<T> itemFactory)
+	{
+		Check.EnsureNotNull(source, nameof(source));
+		Check.EnsureNotNull(predicate, nameof(predicate));
+		Check.EnsureNotNull(itemFactory, nameof(itemFactory));
+
+		if (source.Any(predicate))
+		{
+			return false;
+		}
+
+		source.Add(itemFactory());
+		return true;
+	}
+
+	/// <summary>
+	/// Removes all items from the collection those satisfy the given <paramref name="predicate"/>.
+	/// </summary>
+	/// <typeparam name="T">Type of the items in the collection</typeparam>
+	/// <param name="source">The collection</param>
+	/// <param name="predicate">The condition to remove the items</param>
+	/// <returns>List of removed items</returns>
+	public static IList<T> RemoveAll<T>([NotNull] this ICollection<T> source, Func<T, bool> predicate)
+	{
+		var items = source.Where(predicate).ToList();
+
+		foreach (var item in items)
+		{
+			source.Remove(item);
+		}
+
+		return items;
+	}
+
+	/// <summary>
+	/// Removes all items from the collection those satisfy the given <paramref>
+	///     <name>predicate</name>
+	/// </paramref>
+	/// .
+	/// </summary>
+	/// <typeparam name="T">Type of the items in the collection</typeparam>
+	/// <param name="source">The collection</param>
+	/// <param name="items">Items to be removed from the list</param>
+	public static void RemoveAll<T>([NotNull] this ICollection<T> source, IEnumerable<T> items)
+	{
+		foreach (var item in items)
+		{
+			source.Remove(item);
+		}
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="dictionary"></param>
+	/// <param name="key"></param>
+	/// <param name="value"></param>
+	/// <typeparam name="TKey"></typeparam>
+	/// <typeparam name="TValue"></typeparam>
+	/// <returns></returns>
+	public static IDictionary<TKey, TValue> Set<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue value)
+	{
+		dictionary[key] = value;
+		return dictionary;
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="dictionary"></param>
+	/// <param name="key"></param>
+	/// <param name="func"></param>
+	/// <typeparam name="TKey"></typeparam>
+	/// <typeparam name="TValue"></typeparam>
+	/// <typeparam name="TRef"></typeparam>
+	public static void TryGetValue<TKey, TValue, TRef>(this IDictionary<TKey, TValue> dictionary, TKey key, Action<TRef> func)
+	{
+		if (!dictionary.TryGetValue(key, out var value))
+		{
+			return;
+		}
+
+		var refValue = (TRef)System.Convert.ChangeType(value, typeof(TRef));
+		func(refValue);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="dictionary"></param>
+	/// <param name="key"></param>
+	/// <param name="func"></param>
+	/// <typeparam name="TKey"></typeparam>
+	/// <typeparam name="TRef"></typeparam>
+	public static void TryGetValue<TKey, TRef>(this IDictionary<TKey, object> dictionary, TKey key, Action<TRef> func)
+	{
+		if (!dictionary.TryGetValue(key, out var value))
+		{
+			return;
+		}
+
+		var refValue = (TRef)value;
+		func(refValue);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="dictionary"></param>
+	/// <param name="key"></param>
+	/// <param name="func"></param>
+	/// <typeparam name="TKey"></typeparam>
+	/// <typeparam name="TValue"></typeparam>
+	public static void TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Action<TValue> func)
+	{
+		if (!dictionary.TryGetValue(key, out var value))
+		{
+			return;
+		}
+
+		func(value);
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="dictionary"></param>
+	/// <param name="key"></param>
+	/// <param name="comparison"></param>
+	/// <typeparam name="TValue"></typeparam>
+	/// <returns></returns>
+	public static TValue GetValue<TValue>(this IDictionary<string, TValue> dictionary, string key, StringComparison comparison)
+	{
+		var item = dictionary.FirstOrDefault(t => t.Key.Equals(key, comparison));
+		return item.Value;
+	}
+
+	/// <summary>
+	/// Try get value for specified key from dictionary.
+	/// </summary>
+	/// <typeparam name="TKey">The key type.</typeparam>
+	/// <typeparam name="TValue">The value type.</typeparam>
+	/// <param name="source"></param>
+	/// <param name="key"></param>
+	/// <returns></returns>
+	public static TValue TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return source.TryGetValue(key, out var value) ? value : default;
+	}
+
+	/// <summary>
+	/// Try get value for specified key from dictionary.
+	/// </summary>
+	/// <typeparam name="TKey">The key type.</typeparam>
+	/// <typeparam name="TValue">The value type.</typeparam>
+	/// <param name="source"></param>
+	/// <param name="key"></param>
+	/// <param name="defaultValue">The defaut value if key doesn't exists.</param>
+	/// <returns></returns>
+	/// <exception cref="NullReferenceException"></exception>
+	public static TValue TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key, TValue defaultValue)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return source.TryGetValue(key, out var value) ? value : defaultValue;
+	}
+
+	/// <summary>
+	/// Try get exists value for specified key or set value if not exists.
+	/// </summary>
+	/// <typeparam name="TKey">The type of the key.</typeparam>
+	/// <typeparam name="TValue">The type of the value.</typeparam>
+	/// <param name="source">The source.</param>
+	/// <param name="key">The key.</param>
+	/// <returns>The value.</returns>
+	/// <exception cref="NullReferenceException">Throws if <paramref name="source"/> is null.</exception>
+	public static TValue TryGetOrSetValue<TKey, TValue>(this IDictionary<TKey, TValue> source, TKey key)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		if (source.TryGetValue(key, out var value))
+		{
+			return value;
+		}
+
+		source.Add(key, value);
+		return source[key];
+	}
+
+	/// <summary>
+	/// 
+	/// </summary>
+	/// <param name="source"></param>
+	/// <param name="key"></param>
+	/// <param name="defaultValue"></param>
+	/// <param name="comparison"></param>
+	/// <typeparam name="TValue"></typeparam>
+	/// <returns></returns>
+	/// <exception cref="NullReferenceException"></exception>
+	public static TValue TryGetValue<TValue>(this IDictionary<string, TValue> source, string key, TValue defaultValue, StringComparison comparison)
+	{
+		if (source == null)
+		{
+			throw new NullReferenceException();
+		}
+
+		return source.Keys.Contains(key, comparison) ? source.FirstOrDefault(t => t.Key.Equals(key, comparison)).Value : defaultValue;
+	}
+
+	/// <summary>
+	/// Gets index of item.
+	/// </summary>
+	/// <param name="enumerable"></param>
+	/// <param name="item"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	/// <exception cref="ArgumentNullException"></exception>
+	public static int IndexOf<T>(this IEnumerable<T> enumerable, T item)
+	{
+		if (enumerable == null)
+			throw new ArgumentNullException(nameof(enumerable));
+
+		var i = 0;
+		foreach (var element in enumerable)
+		{
+			if (Equals(element, item))
+			{
+				return i;
+			}
+
+			i++;
+		}
+
+		return -1;
+	}
+
+	/// <summary>
+	/// Gets index of item which matches the predicate.
+	/// </summary>
+	/// <param name="enumerable"></param>
+	/// <param name="predicate"></param>
+	/// <typeparam name="T"></typeparam>
+	/// <returns></returns>
+	public static int IndexOf<T>(this IEnumerable<T> enumerable, Func<T, bool> predicate)
+	{
+		var i = 0;
+		foreach (var element in enumerable)
+		{
+			if (predicate(element))
+			{
+				return i;
+			}
+
+			i++;
+		}
+
+		return -1;
+	}
 }
\ No newline at end of file
diff --git a/Source/Euonia.Core/Reflection/Reflect.cs b/Source/Euonia.Core/Reflection/Reflect.cs
index d250674..8f8c82a 100644
--- a/Source/Euonia.Core/Reflection/Reflect.cs
+++ b/Source/Euonia.Core/Reflection/Reflect.cs
@@ -21,10 +21,7 @@ public static class Reflect
 	/// Or, the property is static.</exception>
 	public static PropertyInfo GetProperty<T>(Expression<Func<T>> expression)
 	{
-		if (expression == null)
-		{
-			throw new ArgumentNullException(nameof(expression));
-		}
+		ArgumentAssert.ThrowIfNull(expression, nameof(expression));
 
 		if (expression.Body is not MemberExpression memberExpression)
 		{
@@ -62,10 +59,7 @@ public static PropertyInfo GetProperty<T>(Expression<Func<T, object>> expression
 	/// <exception cref="ArgumentException"></exception>
 	public static PropertyInfo GetProperty<T, TResult>(Expression<Func<T, TResult>> expression)
 	{
-		if (expression == null)
-		{
-			throw new ArgumentNullException(nameof(expression));
-		}
+		ArgumentAssert.ThrowIfNull(expression, nameof(expression));
 
 		PropertyInfo result;
 
@@ -659,7 +653,9 @@ public static PropertyInfo GetProperty<TValue>(Expression<Func<TTarget, TValue>>
 	{
 		var info = Reflect.GetMemberInfo(expression) as PropertyInfo;
 		if (info == null)
+		{
 			throw new ArgumentException("Member is not a property");
+		}
 
 		return info;
 	}
@@ -673,7 +669,9 @@ public static FieldInfo GetField(Expression<Func<TTarget, object>> expression)
 	{
 		var info = Reflect.GetMemberInfo(expression) as FieldInfo;
 		if (info == null)
+		{
 			throw new ArgumentException("Member is not a field");
+		}
 
 		return info;
 	}
@@ -688,10 +686,7 @@ public static FieldInfo GetField(Expression<Func<TTarget, object>> expression)
 	/// <exception cref="ArgumentNullException">property</exception>
 	public static void SetValue<TValue>(TTarget item, TValue value, Expression<Func<TTarget, TValue>> property)
 	{
-		if (property == null)
-		{
-			throw new ArgumentNullException(nameof(property));
-		}
+		ArgumentAssert.ThrowIfNull(property, nameof(property));
 
 		var propertyInfo = GetProperty(property);
 
diff --git a/Source/Euonia.Modularity/Dependency/ILazyServiceProvider.cs b/Source/Euonia.Modularity/Dependency/ILazyServiceProvider.cs
index 8ec6a0e..e64fa0d 100644
--- a/Source/Euonia.Modularity/Dependency/ILazyServiceProvider.cs
+++ b/Source/Euonia.Modularity/Dependency/ILazyServiceProvider.cs
@@ -1,7 +1,7 @@
 namespace System;
 
 /// <summary>
-/// <see cref="ILazyServiceProvider"/>
+/// Represents a service provider that can be used to retrieve services with lazy initialization.
 /// </summary>
 public interface ILazyServiceProvider
 {
@@ -42,7 +42,7 @@ public interface ILazyServiceProvider
 	T GetService<T>(T defaultValue);
 
 	/// <summary>
-	/// 
+	/// Get service of type <paramref name="serviceType"/> from the <see cref="IServiceProvider"/>.
 	/// </summary>
 	/// <param name="serviceType"></param>
 	/// <param name="defaultValue"></param>
@@ -92,7 +92,7 @@ public interface ILazyServiceProvider
 	/// <summary>
 	/// Get service of type <paramref name="serviceType"/> from the <see cref="IServiceProvider"/>.
 	/// </summary>
-	/// <param name="serviceType"></param>
+	/// <param name="serviceType">An object that specifies the type of service object to get.</param>
 	/// <param name="serviceKey">An object that specifies the key of service object to get.</param>
 	/// <returns></returns>
 	object GetRequiredKeyedService(Type serviceType, object serviceKey);
@@ -118,7 +118,7 @@ public interface ILazyServiceProvider
 	/// <summary>
 	/// Get service of type <paramref name="serviceType"/> from the <see cref="IServiceProvider"/>.
 	/// </summary>
-	/// <param name="serviceType"></param>
+	/// <param name="serviceType">An object that specifies the type of service object to get.</param>
 	/// <param name="serviceKey">An object that specifies the key of service object to get.</param>
 	/// <param name="factory"></param>
 	/// <returns></returns>
@@ -127,7 +127,7 @@ public interface ILazyServiceProvider
 	/// <summary>
 	/// Get service of type <paramref name="serviceType"/> from the <see cref="IServiceProvider"/>.
 	/// </summary>
-	/// <param name="serviceType"></param>
+	/// <param name="serviceType">An object that specifies the type of service object to get.</param>
 	/// <param name="serviceKey">An object that specifies the key of service object to get.</param>
 	/// <param name="defaultValue"></param>
 	/// <returns></returns>
diff --git a/Source/Euonia.Modularity/Dependency/LazyServiceProvider.cs b/Source/Euonia.Modularity/Dependency/LazyServiceProvider.cs
index 4252300..26df8f2 100644
--- a/Source/Euonia.Modularity/Dependency/LazyServiceProvider.cs
+++ b/Source/Euonia.Modularity/Dependency/LazyServiceProvider.cs
@@ -1,4 +1,5 @@
 using System.Collections.Concurrent;
+using Microsoft.Extensions.DependencyInjection;
 using Nerosoft.Euonia.Modularity;
 
 namespace System;
@@ -33,33 +34,14 @@ public virtual T GetRequiredService<T>()
 		return (T)GetRequiredService(typeof(T));
 	}
 
-	/// <summary>
-	/// 
-	/// </summary>
-	/// <param name="serviceType"></param>
-	/// <returns></returns>
-	/// <exception cref="ArgumentNullException"></exception>
-	/// <exception cref="NullReferenceException"></exception>
+	/// <inheritdoc />
 	public virtual object GetRequiredService(Type serviceType)
 	{
 		return CachedServices.GetOrAdd(new ServiceIdentifier(serviceType), _ => new Lazy<object>(() =>
 		{
-			if (ServiceProvider == null)
-			{
-				throw new ArgumentNullException(nameof(ServiceProvider));
-			}
-
-			if (serviceType == null)
-			{
-				throw new ArgumentNullException(nameof(serviceType));
-			}
-
-			var service = ServiceProvider.GetService(serviceType);
-			if (service == null)
-			{
-				throw new NullReferenceException(nameof(serviceType));
-			}
-
+			ArgumentAssert.ThrowIfNull(ServiceProvider, nameof(ServiceProvider));
+			ArgumentAssert.ThrowIfNull(serviceType, nameof(serviceType));
+			var service = ServiceProvider.GetRequiredService(serviceType);
 			return service;
 		})).Value;
 	}
diff --git a/Source/Euonia.Modularity/Dependency/ServiceIdentifier.cs b/Source/Euonia.Modularity/Dependency/ServiceIdentifier.cs
index bcb47b9..f337162 100644
--- a/Source/Euonia.Modularity/Dependency/ServiceIdentifier.cs
+++ b/Source/Euonia.Modularity/Dependency/ServiceIdentifier.cs
@@ -1,16 +1,34 @@
 namespace Nerosoft.Euonia.Modularity;
 
+/// <summary>
+/// The service identifier.
+/// </summary>
 internal readonly struct ServiceIdentifier : IEquatable<ServiceIdentifier>
 {
+	/// <summary>
+	/// Gets the service key.
+	/// </summary>
 	public object ServiceKey { get; }
 
+	/// <summary>
+	/// Gets the service type.
+	/// </summary>
 	public Type ServiceType { get; }
 
+	/// <summary>
+	/// Initializes a new instance of the <see cref="ServiceIdentifier"/> struct.
+	/// </summary>
+	/// <param name="serviceType"></param>
 	public ServiceIdentifier(Type serviceType)
 	{
 		ServiceType = serviceType;
 	}
 
+	/// <summary>
+	/// Initializes a new instance of the <see cref="ServiceIdentifier"/> struct.
+	/// </summary>
+	/// <param name="serviceKey"></param>
+	/// <param name="serviceType"></param>
 	public ServiceIdentifier(object serviceKey, Type serviceType)
 	{
 		ServiceKey = serviceKey;
@@ -27,6 +45,7 @@ public bool Equals(ServiceIdentifier other)
 		{
 			return ServiceType == other.ServiceType && ServiceKey.Equals(other.ServiceKey);
 		}
+
 		return false;
 	}
 
@@ -41,9 +60,10 @@ public override int GetHashCode()
 		{
 			return ServiceType.GetHashCode();
 		}
+
 		unchecked
 		{
 			return (ServiceType.GetHashCode() * 397) ^ ServiceKey.GetHashCode();
 		}
 	}
-}
+}
\ No newline at end of file