 [A warranty is] an assurance by one party to a contract of the existence of a fact upon which the other party may rely. It is intended precisely to relieve the promisee of any duty to ascertain the fact for himself; it amounts to a promise to indemnify the promisee for any loss if the fact warranted proves untrue, for obviously the promisor cannot control what is already in the past. (Metropolitan Coal Co. v. Howard 1946)