docs: def start(self, wait=True, timeout=None, wait_polling_interval=None):
          """Start b2g, waiting for the adb connection to become stable.
  
          :param wait:
          :param timeout: Maximum time to wait for restart.
          :param wait_polling_interval: Interval at which to poll for device readiness.
          """
          self._logger.info("Starting b2g process")
  
          if timeout is None:
              timeout = self._timeout
  
          if wait_polling_interval is None:
              wait_polling_interval = self._wait_polling_interval
  
          if wait:
              self.wait_for_device_ready(timeout,
                                         after_first=lambda:self.shell_bool("start b2g",
                                                                            timeout=timeout))
          else:
              self.shell_bool("start b2g", timeout=timeout)