[flexcoders] How to use a component extended dynamic class in MXML?

[Shigeru Nakagaki]

Step 1. create "MyWebService" like below.
public dynamic class MyWebService extends WebService

Step 2. write MXML like below.
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml";
layout="absolute" xmlns:pepe="org.pepe.*">
<pepe:MyWebService id="srv">
    <mx:operation name="getMostRecentPosts">
        <mx:request xmlns="">
            <limit>30</limit>
            <offset>0</offset>
            <languageIds>"6"</languageIds>
        </mx:request>
    </mx:operation>
</pepe:MyWebService>

Then compiler said "Could not resolve mx:operation to a component
implementation".

What is the problem about this code?