public function apply()
    {
        if ($this->config->hasKey(self::REGISTER)) {
            $registerConfig = $this->config->getSubConfig(self::REGISTER);
            $this->register($registerConfig->getArrayCopy());
        }

        if ($this->config->hasKey(self::UNREGISTER)) {
            $unregisterConfig = $this->config->getSubConfig(self::UNREGISTER);
            $this->unregister($unregisterConfig->getArrayCopy());
        }

        if ($this->config->hasKey(self::DEFAULTLAYOUT)) {
            $this->setDefault($this->config->getKey(self::DEFAULTLAYOUT));
        }
    }