[Fact]
public void RenderCustomControl()
{
    using MemoryStream mem = new MemoryStream();
    using StreamWriter sw = new StreamWriter(mem);
    using HtmlTextWriter writer = new HtmlTextWriter(sw);

    // Set attributes and values along with attributes and styles  
    // attribute defined for a <span> element.
    writer.AddAttribute(HtmlTextWriterAttribute.Onclick, "alert('Hello');");
    writer.AddAttribute("CustomAttribute", "CustomAttributeValue");
    writer.AddStyleAttribute(HtmlTextWriterStyle.Color, "Red");
    writer.AddStyleAttribute("Customstyle", "CustomStyleValue");
    writer.RenderBeginTag(HtmlTextWriterTag.Span);
    // Create a space and indent the markup inside the 
    // <span> element.
    writer.WriteLine();
    writer.Indent++;
    writer.Write("Hello");
    writer.WriteLine();

    // Controls the encoding of markup attributes
    // for an <img> element. Simple known values 
    // do not need encoding.
    writer.AddAttribute(HtmlTextWriterAttribute.Alt,
        "Encoding, \"Required\"",
        true);
    writer.AddAttribute("myattribute",
        "No &quot;encoding &quot; required",
        false);
    writer.RenderBeginTag(HtmlTextWriterTag.Img);
    writer.RenderEndTag();
    writer.WriteLine();

    // Create a non-standard markup element.
    writer.RenderBeginTag("MyTag");
    writer.Write("Contents of MyTag");
    writer.RenderEndTag();
    writer.WriteLine();

    // Create a manually rendered <img> element
    // that contains an alt attribute.
    writer.WriteBeginTag("img");
    writer.WriteAttribute("alt", "A custom image.");
    writer.Write(HtmlTextWriter.TagRightChar);
    writer.WriteEndTag("img");
    writer.WriteLine();

    writer.Indent--;
    writer.RenderEndTag();

    writer.Flush();
    mem.Position = 0;
    string html = Encoding.UTF8.GetString(mem.GetBuffer());

    const string expected = "<span onclick=\"alert(&#39;Hello&#39;);\" CustomAttribute=\"CustomAttributeValue\" style=\"color:Red;Customstyle:CustomStyleValue;\">\r\n\tHello\r\n\t<img alt=\"Encoding, &quot;Required&quot;\" myattribute=\"No &quot;encoding &quot; required\" />\r\n\t<MyTag>\r\n\t\tContents of MyTag\r\n\t</MyTag>\r\n\t<img alt=\"A custom image.\"></img>\r\n</span>";
    Assert.Equal(expected, html);
}