Add back removed XML comments during refactoring

src/Lucene.Net.Grouping/GroupDocs.cs

@@ -75,6 +75,10 @@ public GroupDocs(float score, float maxScore, int totalHits, ScoreDoc[] scoreDoc
 
         #region Explicit interface implementations
 
+        /// <summary>
+        /// LUCENENET specific method to provide an object-based implementation of <see cref="GroupValue"/>.
+        /// </summary>
+        [SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "Lucene's design requires some array properties")]
         object IGroupDocs.GroupValue => GroupValue;
 
         #endregion
@@ -86,16 +90,38 @@ public GroupDocs(float score, float maxScore, int totalHits, ScoreDoc[] scoreDoc
     /// </summary>
     public interface IGroupDocs
     {
+        /// <summary>
+        /// The groupField value for all docs in this group; this
+        /// may be null if hits did not have the groupField.
+        /// </summary>
         object GroupValue { get; }
 
+        /// <summary>
+        /// Max score in this group
+        /// </summary>
         float MaxScore { get; }
 
+        /// <summary>
+        /// Overall aggregated score of this group (currently only set by join queries).
+        /// </summary>
         float Score { get; }
 
+        /// <summary>
+        /// Hits; this may be <see cref="FieldDoc"/> instances if the
+        /// withinGroupSort sorted by fields.
+        /// </summary>
+        [SuppressMessage("Microsoft.Performance", "CA1819", Justification = "Lucene's design requires some writable array properties")]
         ScoreDoc[] ScoreDocs { get; }
 
+        /// <summary>
+        /// Total hits within this group
+        /// </summary>
         int TotalHits { get; }
 
+        /// <summary>
+        /// Matches the groupSort passed to <see cref="AbstractFirstPassGroupingCollector{TGroupValue}"/>.
+        /// </summary>
+        [SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "Lucene's design requires some array properties")]
         object[] GroupSortValues { get; }
     }
 }

src/Lucene.Net.Grouping/SearchGroup.cs

@@ -82,6 +82,9 @@ public override int GetHashCode()
 
         #region Explicit interface implementations
 
+        /// <summary>
+        /// LUCENENET specific implementation to provide an object-based implementation of <see cref="GroupValue"/>.
+        /// </summary>
         object ISearchGroup.GroupValue
         {
             get => GroupValue;
@@ -490,8 +493,20 @@ public static ICollection<SearchGroup<T>> Merge<T>(IList<ICollection<SearchGroup
     /// </summary>
     public interface ISearchGroup
     {
+        /// <summary>
+        /// The value that defines this group
+        /// </summary>
         object GroupValue { get; set; }
 
+        /// <summary>
+        /// The sort values used during sorting. These are the
+        /// groupSort field values of the highest rank document
+        /// (by the groupSort) within the group.  Can be
+        /// <c>null</c> if <c>fillFields=false</c> had
+        /// been passed to <see cref="AbstractFirstPassGroupingCollector{TGroupValue}.GetTopGroups(int, bool)"/>
+        /// </summary>
+        [SuppressMessage("Microsoft.Performance", "CA1819", Justification = "Lucene's design requires some writable array properties")]
+        [WritableArray]
         object[] SortValues { get; set; }
     }
 }

src/Lucene.Net.Grouping/TopGroups.cs

@@ -90,6 +90,9 @@ public TopGroups(TopGroups<TGroupValue> oldTopGroups, int? totalGroupCount)
 
         #region Explicit interface implementations
 
+        /// <summary>
+        /// LUCENENET specific method to provide an <see cref="IGroupDocs"/>-based implementation of <see cref="Groups"/>.
+        /// </summary>
         IList<IGroupDocs> ITopGroups.Groups => new CastingListAdapter<GroupDocs<TGroupValue>, IGroupDocs>(Groups);
 
         #endregion
@@ -281,23 +284,46 @@ public static TopGroups<T> Merge<T>(TopGroups<T>[] shardGroups, Sort groupSort,
     /// </summary>
     public interface ITopGroups
     {
+        /// <summary>
+        /// Number of documents matching the search
+        /// </summary>
         int TotalHitCount { get; }
 
+        /// <summary>
+        /// Number of documents grouped into the topN groups
+        /// </summary>
         int TotalGroupedHitCount { get; }
 
+        /// <summary>
+        /// The total number of unique groups. If <c>null</c> this value is not computed.
+        /// </summary>
         int? TotalGroupCount { get; }
 
         /// <summary>
+        /// Group results in groupSort order
+        /// <para />
         /// LUCENENET specific - this uses IList instead of an array
         /// as it would require a new array to be created each time
         /// the property is accessed.
         /// </summary>
         IList<IGroupDocs> Groups { get; }
 
+        /// <summary>
+        /// How groups are sorted against each other
+        /// </summary>
+        [SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "Lucene's design requires some array properties")]
         SortField[] GroupSort { get; }
 
+        /// <summary>
+        /// How docs are sorted within each group
+        /// </summary>
+        [SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "Lucene's design requires some array properties")]
         SortField[] WithinGroupSort { get; }
 
+        /// <summary>
+        /// Highest score across all hits, or
+        /// <see cref="float.NaN"/> if scores were not computed.
+        /// </summary>
         float MaxScore { get; }
     }
 }