code: async def start(self):
          
  
          successful = 0
  
          try:
              for adapter in self.adapters:
                  await adapter.start()
                  successful += 1
  
              self._started = True
          except:
              for adapter in self.adapters[:successful]:
                  await adapter.stop()
  
              raise
docs: Start all adapters managed by this device adapter.
  
          If there is an error starting one or more adapters, this method will
          stop any adapters that we successfully started and raise an exception.