/// <summary>
/// Returns a data-producer that yields the first instance of each unique
/// value in the sequence; subsequent identical values are ignored.
/// </summary>
/// <param name="source">The data-producer</param>
/// <remarks>This will force the first instance of each unique value to be buffered</remarks>
public static IDataProducer <TSource> Distinct <TSource>(this IDataProducer <TSource> source)
{
return(source.Distinct(EqualityComparer <TSource> .Default));
}