Craft\Neo_CriteriaModel::_indexOfRootBlock PHP Method

    private function _indexOfRootBlock($elements, Neo_BlockModel $block)
    {
        $index = $this->_indexOfBlock($elements, $block);
        if ($block->level == 1) {
            return $index;
        }
        for ($i = $index - 1; $i >= 0; $i--) {
            $element = $elements[$i];
            if ($element->level == 1) {
                return $i;
            }
        }
        return -1;
    }