code: func (e *ClientExecutor) Release() []error {
  	errs := e.Volumes.Release()
  	for _, fn := range e.Deferred {
  		if err := fn(); err != nil {
  			errs = append(errs, err)
  		}
  	}
  	e.Deferred = nil
  	return errs
  }
docs: // Release deletes any items started by this executor.