docs: def powerDown(self):
          """power down the OpenThreadWpan"""
          print '%s call powerDown' % self.port
          if self.__sendCommand(WPANCTL_CMD + 'setprop Daemon:AutoAssociateAfterReset false')[0] != 'Fail':
              time.sleep(0.5)
              if self.__sendCommand(WPANCTL_CMD + 'reset')[0] != 'Fail':
                  self.isPowerDown = True
                  return True
              else:
                  return False
          else:
              return False