code: def stepper_step(self, motor_speed, number_of_steps):
          
          task = asyncio.ensure_future(self.core.stepper_step(motor_speed,
                                                              number_of_steps))
          self.loop.run_until_complete(task)
docs: Move a stepper motor for the number of steps at the specified speed
          This is a FirmataPlus feature.
  
          :param motor_speed: 21 bits of data to set motor speed
  
          :param number_of_steps: 14 bits for number of steps & direction
                                  positive is forward, negative is reverse