extern int j_add_string(struct json_object *obj, const char *key, const char *val);
extern int j_add_boolean(struct json_object *obj, const char *key, int val);
extern int j_add_integer(struct json_object *obj, const char *key, int val);
extern int j_add_string(struct json_object *obj, const char *key, const char *val);
extern int j_add_boolean(struct json_object *obj, const char *key, int val);
extern int j_add_integer(struct json_object *obj, const char *key, int val);