public void Failure_Ok()
{
var error = "error message";
var success = new Failure <object, string>(error);
var successCalled = false;
var failureCalled = false;
success.Do(
onSuccess: o => { successCalled = true; },
onFailure: err => { failureCalled = true; });
Assert.That(successCalled, Is.False);
Assert.That(failureCalled, Is.True);
}