def _get_srv_class(typestring):
    global _loaded_srvs, _srvs_lock
    return _get_class(typestring, "srv", _loaded_srvs, _srvs_lock)
If not loaded, loads the specified srv class then returns an instance
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_library/src/rosbridge_library/internal/ros_loader.py/_get_srv_class