Fix namespace missing backslash / wrong class

namespace Plugin\Theme;

use Core\PluginBase;

use Core\Plugin\Base;

class Plugin extends PluginBase

class Plugin extends Base

{

    public function initialize()

    {

        $this->template->hook->attach('template:layout:head', 'theme:layout/head');

        $this->template->hook->attach('template:layout:top', 'theme:layout/top');

        $this->template->setTemplateOverride('template:header', 'theme:layout/header');

        $this->template->setTemplateOverride('header', 'theme:layout/header');

    }

}