private function generateResolverTypes() : string
    {
        $types = []; 

        foreach($this->services as $serviceName => $serviceDefinition)
        {
            $types[] = var_export($serviceName, true) . ' => ' . Container::RESOLVE_METHOD;
        }

        return "protected \$serviceResolverType = [" . implode(', ', $types) . "];\n";
    }