public errorHandler (err: Error) {
   switch (err.message) {
     case 'X-Hub-Signature does not match blob signature':
     case 'No X-Hub-Signature found on request':
       logger.error('Go to https://github.com/settings/apps/YOUR_APP and verify that the Webhook secret matches the value of the WEBHOOK_SECRET environment variable.')
       break
     case 'error:0906D06C:PEM routines:PEM_read_bio:no start line':
     case '{"message":"A JSON web token could not be decoded","documentation_url":"https://developer.github.com/v3"}':
       logger.error('Your private key (usually a .pem file) is not correct. Go to https://github.com/settings/apps/YOUR_APP and generate a new PEM file. If you\'re deploying to Now, visit https://probot.github.io/docs/deployment/#now.')
       break
     default:
       logger.error(err)
   }
 }

    waterline_obj.initialize(orm.config, (err, ontology) => {
        if (err != null)
            return callback(err);
        else if (ontology == null || ontology.connections == null || ontology.collections == null
            || ontology.connections.length === 0 || ontology.collections.length === 0) {
            logger.error('waterline_obj.initialize::ontology =', ontology, ';');
            return callback(new TypeError('Expected ontology with connections & waterline_collections'));
        }

        // Tease out fully initialised models.
        logger.info('Waterline initialised with:\t', Object.keys(ontology.collections), ';');
        return callback(null, { connection: ontology.connections, collections: ontology.collections });
    });

export default async function tweetImage(logger: Logger) {
  try {
    const { fileName, file } = await getRandomPicture();

    const b64Picture = file.toString('base64');
    const uploadedPicture = await t.post('media/upload', {
      stringify_ids: true,
      media_data: b64Picture,
    });
    const mediaParams = {
      stringify_ids: true,
      // @ts-ignore
      media_id: uploadedPicture.data.media_id_string,
      alt_text,
    };

    await t.post('media/metadata/create', mediaParams);
    const tweet = await t.post('statuses/update', {
      stringify_ids: true,
      status: config.twitter.tweetMessage,
      // @ts-ignore
      media_ids: [uploadedPicture.data.media_id_string],
    });

    logger.info({
      status: config.twitter.tweetMessage,
      // @ts-ignore
      mediaIds: uploadedPicture.data.media_id_string,
      image: fileName,
      // @ts-ignore
      tweet: tweet.data.id_str,
    });
  } catch (e) {
    logger.error(e);
  }
}