code: def new_actuator(joint, act_type="actuator", **kwargs):
      
      element = ET.Element(act_type, attrib=kwargs)
      element.set("joint", joint)
      return element
docs: Creates an actuator tag with attributes specified by @**kwargs.
  
      Args:
          joint: type of actuator transmission.
              see all types here: http://mujoco.org/book/modeling.html#actuator
          act_type (str): actuator type. Defaults to "actuator"