65 LmMessageNode *luaL_checkLmMessageNode (lua_State *L, int index)

    66 {

    67 	void *object;

    68 	luaL_argcheck (L, lua_type (L, index) == LUA_TUSERDATA, index, "loudmouth message or message node expected");

    69 	object = lua_touserdata (L, index);

    70 	lua_getmetatable (L, index);

    71 	luaL_getmetatable (L, "loudmouth.message");

    72 	luaL_getmetatable (L, "loudmouth.message_node");

    73 	if (lua_rawequal (L, -2, -3)) // Message

    74 		object = (void *) lm_message_get_node (((llm_message_t *) object)->message);

    75 	else if (lua_rawequal (L, -1, -3)) // Node

    76 		object = (void *) (((llm_message_node_t *) object)->message_node);

    77 	else

    78 		luaL_argerror (L, index, "loudmouth message or message node expected");

    79 	lua_pop (L, 3);

    80 	return (LmMessageNode *) object;

    81 }

    82