public function isPropertyPrivate($className, $propertyName)
    {
        $className = $this->prepareClassReflectionForUsage($className);
        return (isset($this->classReflectionData[$className][self::DATA_CLASS_PROPERTIES][$propertyName][self::DATA_PROPERTY_VISIBILITY])
            && $this->classReflectionData[$className][self::DATA_CLASS_PROPERTIES][$propertyName][self::DATA_PROPERTY_VISIBILITY] === self::VISIBILITY_PRIVATE);
    }