make a JAXB2/xjc Plugin

With NB 6.9.1 I want to write a Plugin for xjc, so it generates a
toString method like this:

<xs:annotation>
                            <xs:appinfo>
                                <ts:myToString>name</ts:myToString>
                            </xs:appinfo> </xs:annotation>

It's supposed to generate a toString method for Person(name,age),
which returns just the name of the object

But I'm baffled by all kinds of difficulties:
1: what should be in META_INF/Services ?
2: which namespace should I use where ?
3: which namespaces should be in .xsd ?

Can anyone help me out, maybe with a simple but complet NB project ?

For now I have these classes:

package com.sun.tools.xjc.addon.myToString;
public class Const {
    public static final String NS =
"http://jaxb.dev.java.net/plugin/myToString";
}
------
package com.sun.tools.xjc.addon.myToString;

import com.sun.tools.xjc.Options;
import com.sun.tools.xjc.Plugin;
import com.sun.tools.xjc.addon.code_injector.Const;
import com.sun.tools.xjc.model.CPluginCustomization;
import com.sun.tools.xjc.outline.ClassOutline;
import com.sun.tools.xjc.outline.Outline;
import com.sun.tools.xjc.util.DOMUtils;

import java.util.Collections;
import java.util.List;
import org.xml.sax.ErrorHandler;
public class PluginImpl extends Plugin {

    public String getOptionName() {
        return "XmyToString";
    }

    public List<String> getCustomizationURIs() {
        return Collections.singletonList(Const.NS);
    }

    public boolean isCustomizationTagName(String nsUri, String
localName) {
        return nsUri.equals(Const.NS) &&
localName.equals("myToString");
    }

    public String getUsage() {
        return " -XmyToString : make a toString method.";
    }

    public boolean run(Outline model, Options opt, ErrorHandler
errorHandler) {
        for (ClassOutline co : model.getClasses()) {
            CPluginCustomization c =
co.target.getCustomizations().find(Const.NS, "myToString");
            if (c == null) {
                continue; // no customization --- nothing to inject
here
            }
            c.markAsAcknowledged();

            // inject the specified code fragment into the
implementation class.
            co.implClass.direct("\npublic String toString() {\n" +
                                " return " +
DOMUtils.getElementText(c.element) + ";\n" +
                                "}\n");
        }

        return true;
    }
}