California law does not recognize the concept of constructive termination in the context of ordinary commercial contracts between business entities. The social policies that allow constructive termination in the employment and landlord-tenant contexts do not apply to ordinary commercial contracts. Also, the contract in this case specifically provided four means of terminating the contract, none of which involved a constructive termination. Usage in the trade can’t vary the contract’s unambiguous terms, and if those terms leave a party without a remedy, it may challenge the contract as unconscionable or blame itself for entering into a disadvantageous contract. In any case, there was no termination here because plaintiff continued its performance under the contract until the contract expired of its own terms. Mere breach, even a severe one, by the defendant did not terminate the contract. And a letter from defendant implicitly threatening termination for cause if plaintiff stopped performance was not coercion sufficient to excuse plaintiff’s continued performance.