code: function (options) {
          options = options || {};
          var qs = '';
          if (typeof options === 'string') {
              qs = options;
              options = this.parseOptions(qs);
          }
  
          for (var key in options) {
              if (!(key in DEFAULT_OPTIONS)) {
                  throw new Error('No such option.');
              }
          }
          if (qs.length && !Object.keys(options).length) {
              throw new Error('Invalid argument syntax.');
          }
  
          this.options = extend(DEFAULT_OPTIONS, options);
      }
docs: Prints usage
  @method
  @param {Object} options the options object