/// <summary>
/// Filters a data-producer based on a predicate on each value
/// </summary>
/// <param name="source">The data-producer to be filtered</param>
/// <param name="predicate">The condition to be satisfied</param>
/// <returns>A filtered data-producer; only matching values will raise the DataProduced event</returns>
public static IDataProducer <TSource> Where <TSource>(this IDataProducer <TSource> source,
Func <TSource, bool> predicate)
{
predicate.ThrowIfNull("predicate");
return(source.Where((x, index) => predicate(x)));
}