code: function(response) {
        if (!this.xhr && this.config) {
          if (response) {
            this.xhr = true;
            var self = this;
            setTimeout(function() {
              APICall.complete(self, response);
            }, 1);
          } else {
            this.xhr = ajax(this.url, this.config);
          }
        }
        return this;
      }
docs: If a synchronous ajax call is done (via setting: options.async = false), you must call this function
  after you have attached all your event handlers. You should not attach event handlers after this
  is called.