If you find a buggy test, please file a bug and tag one of the suggested reviewers.

PASS If payment method identifier are supported, resolve promise with true.
PASS If request.[[state]] is "created", then return a promise that resolves to true for known method.
PASS All methods are unsupported
PASS Mix of supported and unsupported methods, at least one method is supported.
PASS If request.[[state]] is "interactive", then return a promise rejected with an "InvalidStateError" DOMException.
PASS If request.[[state]] is "closed", then return a promise rejected with an "InvalidStateError" DOMException.