List all videos uploaded by a certain user.

def find_by_user(user_id, _connection=None, page_size=100, page_number=0,
        sort_by=enums.DEFAULT_SORT_BY, sort_order=enums.DEFAULT_SORT_ORDER):
        """
        List all videos uploaded by a certain user.
        """
        return connection.ItemResultSet('find_videos_by_user_id',
            Video, _connection, page_size, page_number, sort_by, sort_order,
            user_id=user_id)