code: def submit_commands(self, devices, execution):
          
          fs = []
          for device in devices:
              if device[key_id_] != self.device_id:
                  logging.warning('Ignoring command for unknown device: %s'
                                  % device[key_id_])
                  continue
              if not execution:
                  logging.warning('Ignoring noop execution')
                  continue
              for command in execution:
                  f = self.executor.submit(
                      self.dispatch_command, **command
                  )
                  fs.append(f)
          return fs
docs: Submit device command executions.
  
          Returns: a list of concurrent.futures for scheduled executions.