List playlists by specific reference_ids.

def find_by_reference_ids(reference_ids, connection=None, page_size=100,
        page_number=0, sort_by=DEFAULT_SORT_BY, sort_order=DEFAULT_SORT_ORDER):
        """
        List playlists by specific reference_ids.
        """
        reference_ids = ','.join([str(i) for i in reference_ids])
        return pybrightcove.connection.ItemResultSet(
            "find_playlists_by_reference_ids", Playlist, connection, page_size,
            page_number, sort_by, sort_order, reference_ids=reference_ids)