private function loadSummaryPosition(): ?int
    {
        $return = null;
        $possSummaryPos = $this->loadNextDocBlockContent($this->getDocCommentPos());

        if ((int) $possSummaryPos > 0) {
            $possSummaryToken = $this->tokens[$possSummaryPos];

            $return = $this->isSimpleText($possSummaryToken) ? $possSummaryPos : null;
        }

        return $return;
    }