Template method for overriding params
@template
@private
@param {Object} options
@param {String} params
@return {String} The modified params
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;
    }