private function evalClass(ClassMetadata $class)
 {
     $class->setName($class->getName() . '__PROXY__');
     while (class_exists($this->getCanonicalClassName($class))) {
         $class->setName($class->getName() . mt_rand(0, 999));
     }
     $result = @eval((string) $class) !== false;
     return $result;
 }