It still uses real class instead mock class.

I use it to mock class for my fuelphp project. But It still uses real class instead of mock class.
$user = test::double('\Apply\Model_Apply_Token', [
'find_one_by' => null,
]);
var_dump(Model_Apply_Token::find_one_by('uuid', 12341);

It probably is due to that te 'find_one_by'-method is not in the Model_Apply_Token class, but from a class that is extended by that class. Did you try to mock the parent class?