package Ġcom . my book stack . domain Ċ Ċ import Ġcom . my book stack . annotations . Aggregate Ċ import Ġcom . my book stack . domain . book . Book Ċ Ċ @ Aggregate Ċ class ĠLibrary ( private Ġval Ġbooks : ĠList < Book >) Ġ{ Ċ Ċ } Ċ