League\CommonMark\Delimiter\DelimiterStack::searchByCharacter PHP Method

    public function searchByCharacter($characters)
    {
        if (!is_array($characters)) {
            $characters = [$characters];
        }
        $opener = $this->top;
        while ($opener !== null) {
            if (in_array($opener->getChar(), $characters)) {
                break;
            }
            $opener = $opener->getPrevious();
        }
        return $opener;
    }