public function testConstructor()
 {
     $loader = new \Phalcon\DI\Service\Loader();
     $di = $loader->getDI();
     $this->assertInstanceOf('\\Phalcon\\DiInterface', $di);
     $di = new Phalcon\DI\FactoryDefault();
     $loader = new \Phalcon\DI\Service\Loader($di);
     $this->assertInstanceOf('\\Phalcon\\DiInterface', $loader->getDI());
     $this->assertEquals($di, $loader->getDI());
 }