The source code

    /**
     * @class Ext.data.Request
     * A simple Request class used internally to the data package to provide more generalized remote-requests
     * to a DataProxy.
     * TODO Not yet implemented.  Implement in Ext.data.Store#execute
     */
    Ext.data.Request = function(params) {
        Ext.apply(this, params);
    };
    Ext.data.Request.prototype = {
        /**
         * @cfg {String} action
         */
        action : undefined,
        /**
         * @cfg {Ext.data.Record[]/Ext.data.Record} rs The Store recordset associated with the request.
         */
        rs : undefined,
        /**
         * @cfg {Object} params HTTP request params
         */
        params: undefined,
        /**
         * @cfg {Function} callback The function to call when request is complete
         */
        callback : Ext.emptyFn,
        /**
         * @cfg {Object} scope The scope of the callback funtion
         */
        scope : undefined,
        /**
         * @cfg {Ext.data.DataReader} reader The DataReader instance which will parse the received response
         */
        reader : undefined
    };