code: function transform (raw, protocol, board) {
    const reducer = (acc, file) => acc.concat([{
      filename: file.filename,
      url: webmUrl(protocol, board, file.tim),
      thumbnail: thumbUrl(protocol, board, file.tim)
    }])
  
    const payload = {
      webms: raw.posts.filter(isWebm).reduce(reducer, [])
    }
  
    if (raw.posts[0].sub) {
      payload.subject = raw.posts[0].sub
    }
  
    return payload
  }
docs: Transforms a 4chan thread payload into a JSON with webm data
  @func    transform
  @param   {Object} raw      Raw thread JSON payload
  @param   {String} protocol Protocol to use for generating links
  @param   {String} board    Board shortname, eg. 'b'
  @returns {Object}          JSON containing thread subject and webm data