public function addXmlAcceptanceCertificateBuyerTitles(\AgentSIB\Diadoc\Api\Proto\Events\ReceiptAttachment $value)
    {
        if ($this->XmlAcceptanceCertificateBuyerTitles === null) {
            $this->XmlAcceptanceCertificateBuyerTitles = new \Protobuf\MessageCollection();
        }

        $this->XmlAcceptanceCertificateBuyerTitles->add($value);
    }