class MockObject
{
	public function checkExpectations() : void
	{
	}
}

/**
 * @template RequestedType
 * @param class-string<RequestedType> $className
 * @return RequestedType&MockObject
 */
function mock(string $className)
{
	$instance = eval("there be dragons");

	return $instance;
}

class A {
	public function foo() : void {}
}

/**
 * @template UnknownType
 * @param class-string<UnknownType> $className
 */
function useMockTemplated(string $className) : void
{
	mock($className)->checkExpectations();
}

mock(A::class)->foo(); // good
mock(A::class)->checkExpectations(); // good
mock(A::class)->notFoo(); // bad