bool send_error(struct meshlink_handle *mesh, struct connection_t *, request_error_t, const char *);
bool send_ping(struct meshlink_handle *mesh, struct connection_t *);
bool send_pong(struct meshlink_handle *mesh, struct connection_t *);
bool send_error(struct meshlink_handle *mesh, struct connection_t *, request_error_t, const char *);
bool send_ping(struct meshlink_handle *mesh, struct connection_t *);
bool send_pong(struct meshlink_handle *mesh, struct connection_t *);