public static List <TSource> ToList <TSource>(this IEnumerable <TSource> source)
{
if (source == null)
{
throw Error.ArgumentNull("source");
}
IIListProvider <TSource> listProvider = source as IIListProvider <TSource>;
return(listProvider != null?listProvider.ToList() : new List <TSource>(source));
}
public List <IGrouping <TKey, TElement> > ToList()
{
IIListProvider <IGrouping <TKey, TElement> > lookup = Lookup <TKey, TElement> .Create(_source, _keySelector, _elementSelector, _comparer);
return(lookup.ToList());
}