code: func (f *DeltaFIFO) List() []interface{} {
  	f.lock.RLock()
  	defer f.lock.RUnlock()
  	list := make([]interface{}, 0, len(f.items))
  	for _, item := range f.items {
  		// Copy item's slice so operations on this slice (delta
  		// compression) won't interfere with the object we return.
  		item = copyDeltas(item)
  		list = append(list, item.Newest().Object)
  	}
  	return list
  }
docs: // List returns a list of all the items; it returns the object
  // from the most recent Delta.
  // You should treat the items returned inside the deltas as immutable.