/// <summary>Determines whether a sequence contains a specified element by using the default equality comparer.</summary>
/// <returns>true if the source sequence contains an element that has the specified value; otherwise, false.</returns>
/// <param name="source">A sequence in which to locate a value.</param>
/// <param name="value">The value to locate in the sequence.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> is null.</exception>
public static IBindable <bool> Contains <TSource>(this IBindableCollection <TSource> source, TSource value) where TSource : class
{
return(source.Contains(value, null));
}