Katherine worked on developing the iPhone 10 for Apple. Katherine's salary was $300,000 per year. Her work was responsible for a function of the phone that consumers loved and the 1. iPhone 10 surpassed all estimates for sales because of that feature. Tim Cook, Apple's CEO, was so impressed he sent her a signed memo promising her a bonus of $500 million. As CEO of Apple, Tim Cook had the authority to do that. However, the next day he sent Katherine a memo saying he changed his mind and instead was giving her a $1,000 gift certificate to the Apple store as a bonus. While Katherine was fantasizing as to how she was going to spend her $500 million, she didn't spend any of it. Katherine sues Apple and Tim Cook for the $500 million. You are the judge. Decide who wins the case and why?