/// <summary>
/// Returns a set of elements which have all the given class names.
/// </summary>
/// <param name="elements">The elements to take as source.</param>
/// <param name="classNames">A string representing the list of class names to match; class names are separated by whitespace.</param>
/// <returns>A collection of HTML elements.</returns>
public static HtmlElementCollection GetElementsByClassName(this INodeList elements, String classNames)
{
var result = new List <IElement>();
var names = classNames.SplitSpaces();
if (names.Length > 0)
{
elements.GetElementsByClassName(names, result);
}
return(new HtmlElementCollection(result));
}