How to use the scramjet.StringStream.from function in scramjet

const request = require("request");
const rp = require("request-promise-native");
const { StringStream } = require("scramjet");

StringStream.from(                                 // fetch your API to a scramjet stream
    request("https://api.example.org/v1/shows/list")
)
    .setOptions({maxParallel: 4})                  // set your options
    .lines()                                       // split the stream by line
    .parse(theirShow => {                          // parse strings to data
        return {
            id: theirShow.id,
            title: theirShow.name,
            url: theirShow.url
        };
    })
    .map(async myShow => rp({                      // use asynchronous mapping (for example send requests)
        method: "POST",
        simple: true,
        uri: `http://api.local/set/${myShow.id}`,
        body: JSON.stringify(myShow)

export const getStream = function (cityName, url, averagingPeriod, source, orgUrl) {
  const { metadata } = source;
  const match = url.match(/[\w]{2}_([\w.]{2,})_([\d]{4})(?:_gg)?.txt/);
  const parameter = match[1].toLowerCase().replace('.', '');
  const year = match[2];
  const unit = getUnit(parameter);
  const dayPosition = averagingPeriod.value === 1 ? 0 : 1;

  const fewDaysAgo = +Number(moment.tz(timezone).subtract(4, 'days').format('DDD'));
  log.verbose(`Fetching data from ${url}`);

  const stations = {};
  return StringStream.from(
    request(url)
  )
    .lines(StringStream.SPLIT_LINE)
    .map(x => x.replace(/\s+/g, ' ').replace(/^\s+|\s+$/g, ''))
    .parse(
      row =>
        row
          .trim()
          .split(/\s+/g)
    )
    .shift(1, ([header]) => {
      header
        .slice(2)
        .forEach((x, i) => {
          if (+x) {
            stations[i] = Object.assign(metadata[x]);