+memcached_return memcached_do(memcached_st *ptr, unsigned int server_key, char *commmand,
+ size_t command_length, char with_flush);
+memcached_return memcached_version(memcached_st *ptr);
+memcached_return value_fetch(memcached_st *ptr,
+ char *buffer,
+ memcached_result_st *result,
+ unsigned int server_key);
+void server_list_free(memcached_st *ptr, memcached_server_st *servers);