package Ġio . ple o . ant ae us . core . exceptions Ċ Ċ class ĠU nb ill able Invoice ( invoice Id : ĠInt , Ġreason : ĠString ) Ġ: ĊĠĠĠ ĠException (" Invoice Ġ'$ invoice Id ' Ġshould Ġnot Ġbe Ġb illed Ġbecause : Ġ$ reason ") Ċ