code: function normalizeOptions(options) {
  
      var opts = {};
  
      if (typeof options === 'string') {
          opts = {
              url: options
          };
      } else if (_.isPlainObject(options)) {
          opts = _.clone(options);
      }
  
      return opts;
  }
docs: normalize options. if options is a string, treat it as a url. otherwise
  clone it and return a new copy.
  @private
  @function normalizeOptions
  @param   {Object | String} options a url string or options object
  @returns {Object}