docs: def sendUpdate(self, data):
          """This sends the status update to the master-side
          L{buildbot.process.step.RemoteCommand} object, giving it a sequence
          number in the process. It adds the update to a queue, and asks the
          master to acknowledge the update so it can be removed from that
          queue."""
  
          if not self.running:
              # .running comes from service.Service, and says whether the
              # service is running or not. If we aren't running, don't send any
              # status messages.
              return
          # the update[1]=0 comes from the leftover 'updateNum', which the
          # master still expects to receive. Provide it to avoid significant
          # interoperability issues between new workers and old masters.
          if self.remoteStep:
              update = [data, 0]
              updates = [update]
              d = self.remoteStep.callRemote("update", updates)
              d.addCallback(self.ackUpdate)
              d.addErrback(self._ackFailed, "WorkerForBuilder.sendUpdate")