def get_more(collection_name, num_to_return, cursor_id):
    """Get a **getMore** message.
    """
    data = __ZERO
    data += bson._make_c_string(collection_name)
    data += struct.pack("<i", num_to_return)
    data += struct.pack("<q", cursor_id)
    return __pack_message(2005, data)