protected function findScopeSelectors($scope, $depth)
    {
        if ($scope->depth === $depth && $scope->selectors) {
            return $scope->selectors;
        }

        if ($scope->children) {
            foreach (array_reverse($scope->children) as $c) {
                if ($s = $this->findScopeSelectors($c, $depth)) {
                    return $s;
                }
            }
        }

        return [];
    }