Under California law, a contract to manage a professional boxer must be in writing, and the manager must be licensed by the state athletic commission. Marco Antonio Barrera is a professional boxer and two-time world champion. In May 2003, Jose Castillo, who was not licensed by the state, orally agreed to assume Barrera’s management. He “understood” that he would be paid in accord with the “practice in the professional boxing industry, but in no case less than ten percent (10%) of the gross revenue” that Barrera generated as a boxer and through endorsements. Among other accomplishments, Castillo negotiated an exclusive promotion contract for Barrera with Golden Boy Promotions, Inc., which is owned and operated by Oscar De La Hoya. Castillo also helped Barrera settle three lawsuits and resolve unrelated tax problems so that Barrera could continue boxing. Castillo did not train Barrera, pick his opponents, or arrange his fights, however. When Barrera abruptly stopped communicating with Castillo, the latter filed a suit in a California state court against Barrera and others, alleging breach of contract. Under what circumstances is a contract with an unlicensed practitioner enforceable? Is the alleged contract in this case enforceable? Why or why not?