code: func (f *DeltaFIFO) Get(obj interface{}) (item interface{}, exists bool, err error) {
  	key, err := f.KeyOf(obj)
  	if err != nil {
  		return nil, false, KeyError{obj, err}
  	}
  	return f.GetByKey(key)
  }
docs: // Get returns the complete list of deltas for the requested item,
  // or sets exists=false.
  // You should treat the items returned inside the deltas as immutable.