code: def _jog(self, axis, direction, step):
          
          jog(axis, direction, step, self.hardware, self._current_mount)
  
          self.current_position = self._position()
          return 'Jog: {}'.format([axis, str(direction), str(step)])
docs: Move the pipette on `axis` in `direction` by `step` and update the
          position tracker