ยง 2501. Undertaking; definition. Undertaking includes 1. Any obligation, whether or not the principal is a party thereto, which contains a covenant by a surety to pay the required amount, as specified therein, if any required condition, as specified therein or as provided in subdivision (c) section 2502, is not fulfilled; and 2. any deposit, made subject to the required condition, of the required amount in legal tender of the United States or in face value of unregistered bonds of the United States or of the state.