public function getParentLocale() {
        if ($this->_parent) {
            return $this->_parent;
        }

        if (!$this->hasConfig('parent')) {
            return null;
        }

        $parent = new Locale($this->getConfig('parent'));
        $parent->initialize();

        // Merge parent config
        $this->addConfig($this->allConfig() + $parent->allConfig());

        $this->_parent = $parent;

        return $parent;
    }