function cmdTestReverseAsyncWithProgress(s, cb, pcb) {
        var result = s.split("").reverse().join("");
        process.nextTick(function () {
            pcb("progress");
            process.nextTick(function () {
                cb(null, result);
            });
        });
    }
@private
Handler for test.reverseAsyncWithProgress command. Reverses the specified string
and then returns the result asynconously, but launches progress event before that.
@param {string} s String to reverse.
@param {Function} cb Callback function of the form cb(err, response)
@param {Function} pcb Progress callback function of the form pcb(message)