text: var _ = require("lodash");
  
  var worker = function (comments) {
    return _.chain(comments)
      .groupBy("username")
      .flatMap((obj, username) => ({ username, comment_count: _.size(obj) }))
      .sortBy((obj) => -obj.comment_count)
      .value();
  };
  
  module.exports = worker;
  