code: func (l *DefaultLifecycle) AbandonAll() error {
  	l.rmu.Lock()
  	defer l.rmu.Unlock()
  
  	moved, err := l.availableTasks.Concat(l.workingTasks.Dest())
  	remaining := len(l.registry) - moved
  
  	l.registry = l.registry[0:remaining]
  	l.wg.Add(-1 * moved)
  
  	return err
  }
docs: // Marks *all* tasks in the queue as having been abandoned. Called by the
  // worker in the Halt() method.