/**
  * {@inheritdoc}
  *
  * @param ChatPostMessagePayload $payload
  */
 protected function getExpectedPayloadData(PayloadInterface $payload)
 {
     /** @var Attachment $attachment */
     $attachment = $payload->getAttachments()->first();
     /** @var AttachmentField $attachmentField */
     $attachmentField = $attachment->getFields()->first();
     return ['channel' => $payload->getChannel(), 'text' => $payload->getText(), 'username' => $payload->getUsername(), 'icon_emoji' => $payload->getIconEmoji(), 'icon_url' => $payload->getIconUrl(), 'unfurl_media' => $payload->getUnfurlMedia(), 'unfurl_links' => $payload->getUnfurlLinks(), 'link_names' => $payload->getLinkNames(), 'parse' => $payload->getParse(), 'attachments' => json_encode([['title' => $attachment->getTitle(), 'title_link' => $attachment->getTitleLink(), 'image_url' => $attachment->getImageUrl(), 'author_name' => $attachment->getAuthorName(), 'author_link' => $attachment->getAuthorLink(), 'author_icon' => $attachment->getAuthorIcon(), 'pre_text' => $attachment->getPreText(), 'text' => $attachment->getText(), 'color' => $attachment->getColor(), 'fallback' => $attachment->getFallback(), 'fields' => [['title' => $attachmentField->getTitle(), 'value' => $attachmentField->getValue(), 'short' => $attachmentField->isShort()]]]])];
 }