protected function getHookList($scope, $hookName)
    {
        $key = $scope . '_' . $hookName;

        if (!isset($this->hookListHash[$key])) {
            $hookList = array();

            if (isset($this->data['Common'][$hookName])) {
                $hookList = $this->data['Common'][$hookName];
            }

            if (isset($this->data[$scope][$hookName])) {
                $hookList = array_merge($hookList, $this->data[$scope][$hookName]);
                usort($hookList, array($this, 'cmpHooks'));
            }

            $normalizedList = array();
            foreach ($hookList as $hookData) {
                $normalizedList[] = $hookData['className'];
            }

            $this->hookListHash[$key] = $normalizedList;
        }

        return $this->hookListHash[$key];
    }