private function getInjector(\ReflectionClass $reflection): InjectorInterface
    {
        if (isset($this->injectors[$reflection->getName()])) {
            //Stated directly
            $injector = $this->get($this->injectors[$reflection->getName()]);
        } else {
            //Auto-injection!
            $injector = $this->get($reflection->getConstant('INJECTOR'));
        }

        if (!$injector instanceof InjectorInterface) {
            throw new InjectionException(sprintf(
                "Class '%s' must be an instance of InjectorInterface for '%s'",
                get_class($injector),
                $reflection->getName()
            ));
        }

        return $injector;
    }