code: function(yargs, classNames, packageName) {
        let pkg = null;
        packageName.split(".").forEach(seg => {
          if (pkg === null) {
            pkg = window[seg];
          } else {
            pkg = pkg[seg];
          }
        });
        classNames.forEach(cmd => {
          require("../../../" + packageName.replace(/\./g, "/") + "/" + cmd);
          let data = pkg[cmd].getYargsCommand();
          yargs.command(data);
        });
      }
docs: Adds commands to Yargs
  
  @param yargs {yargs} the Yargs instance
  @param classNames {String[]} array of class names, each of which is in the `packageName` package
  @param packageName {String} the name of the package to find each command class