code: func (r *TasksService) Cancel(swarmingrpcstaskscancelrequest *SwarmingRpcsTasksCancelRequest) *TasksCancelCall {
  	c := &TasksCancelCall{s: r.s, urlParams_: make(gensupport.URLParams)}
  	c.swarmingrpcstaskscancelrequest = swarmingrpcstaskscancelrequest
  	return c
  }
docs: // Cancel: Cancel a subset of pending tasks based on the tags.
  // Cancellation happens asynchronously, so when this call returns,
  // cancellations will not have completed yet.