mongoose/docs/c-api/mg_mqtt.h/struct_mg_mqtt_proto_data.md

title, decl_name, symbol_kind, signature

title	decl_name	symbol_kind	signature
struct mg_mqtt_proto_data	struct mg_mqtt_proto_data	struct	struct mg_mqtt_proto_data { uint16_t keep_alive; double last_control_time; };

mg_mqtt_proto_data should be in header to allow external access to it