•  Michael orders a package from Amazon. When the package arrives, Michael refuses to accept the package from the delivery person and has him return it to Amazon. Michael subsequently sues Amazon for not receiving his package. What equitable doctrine could Amazon try to assert?

•  Kalen tells Eric that he has a piece of art by Van Gough worth $4mililon. Kalen and Eric enter into a contract for Eric to purchase the art at a discount price of $3million. Eric later finds out that Kalen painted the art himself and refuses to purchase the art pursuant to the contract. Kalen sues Eric for payment. What maxim of equity would prevent Kalen from being successful?