public function load()
    {
        $this->initialize();

        foreach ($this->dataSources as $name => $dataSource) {
            $dataSource->load();

            $this->processItems($dataSource->getItems(), $name);
            $this->processLayouts($dataSource->getLayouts(), $name);
            $this->processIncludes($dataSource->getIncludes(), $name);
        }
    }