private function reverseFindLastUsefulContent(DocBlock $doc, $from)
    {
        for ($index = $from - 1; $index >= 0; --$index) {
            if ($doc->getLine($index)->containsUsefulContent()) {
                return $index;
            }
        }

        return null;
    }
private function reverseFindLastUsefulContent(DocBlock $doc, $from)
    {
        for ($index = $from - 1; $index >= 0; --$index) {
            if ($doc->getLine($index)->containsUsefulContent()) {
                return $index;
            }
        }

        return null;
    }
@param DocBlock $doc
@param int      $from

@return null|int