code: function(options, params) {
          var form = this.getForm(options),
              serializedForm;
          if (form && !this.isFormUpload(options)) {
              serializedForm = Ext.Element.serializeForm(form);
              params = params ? (params + '&' + serializedForm) : serializedForm;
          }
          return params;
      }
docs: Template method for overriding params
  @template
  @private
  @param {Object} options
  @param {String} params
  @return {String} The modified params