code: func (e Entries) Diff(cmp Entries) (Entries, Entries) {
  	added := Entries{}
  	for _, entry := range cmp {
  		if !e.Contains(entry) {
  			added = append(added, entry)
  		}
  	}
  
  	removed := Entries{}
  	for _, entry := range e {
  		if !cmp.Contains(entry) {
  			removed = append(removed, entry)
  		}
  	}
  
  	return added, removed
  }
docs: // Diff compares two entries and returns the added and removed entries.