public static EditableGrouping <K, T> ToEditableGrouping <K, T>(this IEnumerable <T> source, K key)
{
var res = new EditableGrouping <K, T>(key, source);
return(res);
}
public static EditableGrouping <K, T> ToEditableGrouping <K, T>(this IGrouping <K, T> source)
{
var res = new EditableGrouping <K, T>(source.Key, source);
return(res);
}
