Walter worked nights as a clerk in a fast-food store. on his last work shift, walter's boss told him, "i'm really grateful for the year that you have worked here. i am going to give you a bonus of $1,000 in your last paycheck, but i need you to cover johnny’s shift for me and stay a little later." in response, walter stayed later and covered johnny’s shift. when walter got his last paycheck, there was no bonus. if walter sues, the likely result will be: