protected function _slugExists($slug, ServerRequest $request)
    {
        $existingSlug = $this->find('all')
            ->select($this->getAlias() . '.slug')
            ->where([
                $this->getAlias() . '.slug' => $slug,
                $this->getAlias() . '.controller' => $request->getParam('controller'),
                $this->getAlias() . '.action' => $request->getParam('action')
            ])
            ->where($this->_pluginCondition($request))
            ->enableHydration(false)
            ->first();

        return $existingSlug !== null;
    }