code: function(text, lang, callback) {
  
          if (arguments.length == 4) {
              var options = callback;
              callback = arguments[arguments.length - 1];
          }
  
          var uri = url.format({
              pathname: url.resolve(baseAddress, 'lookup'),
              query: {
                  key: dis.APIkey,
                  lang: lang,
                  text: text,
                  ui: options ? options.ui : null,
                  flags: options ? options.flags : null,
              }
          });
  
          makeRequest(uri, callback);
      }
docs: The first two parameters are text and lang, next pararameter, options, is optional; the last parameter is callback function