code: function generateISO_639_2() {
    return fs.ensureDirAsync(OUTPUT_DIR)
      .then(logger('Ensured output directory exists.'))
      .then(() => scrapeUtil.scrapePages(configs))
      .then(({ wiki, loc }) => {
        // add wiki links
        const iso_639_2 = _.mapValues(loc.iso_639_2, (value, key) => {
          const wikiValue = wiki.iso_639_2[key];
  
          value.wikiUrl = wikiValue.wikiUrl;
  
          return value;
        });
  
        // add biblio keys
        _.each(iso_639_2, (value, key) => {
          const bibliographic = value['639-2/B'];
          if (bibliographic) {
            iso_639_2[bibliographic] = value;
          }
        });
  
        delete iso_639_2['qaa-qtz'];
  
        // analytics
        const values = _.values(iso_639_2);
        const bib = _.chain(iso_639_2).pickBy((v, k) => v['639-2/B'] === k).values().value().length;
        const ter = _.chain(iso_639_2).pickBy((v, k) => v['639-2'] === k).values().value().length;
        console.log(`${ter} languages + ${bib} bibliographic = ${values.length} entries`);
  
        return iso_639_2;
      })
      .then(scrapeUtil.renderFiles(FORMATS, FILE_PREFIX, OUTPUT_DIR))
      .then(logger('Rendered output files.'))
      .catch(err => console.error(err));
  }
docs: eslint-disable-next-line camelcase