docs: def set_sensitivity(self, sensitivity=DEFAULT_SENSITIVITY):
          """Set the sensitivity value.
  
          Valid values are 31 (lowest) to 254 (highest), default is 69.
          """
          if sensitivity < 31:
              self._mtreg = 31
          elif sensitivity > 254:
              self._mtreg = 254
          else:
              self._mtreg = sensitivity
          self._power_on()
          self._set_mode(0x40 | (self._mtreg >> 5))
          self._set_mode(0x60 | (self._mtreg & 0x1f))
          self._power_down()