Digester digester = new Digester();
PluginRules rc = new PluginRules();
digester.setRules( rc );
PluginDeclarationRule pdr = new PluginDeclarationRule();
digester.addRule( "root/plugin", pdr );
PluginCreateRule pcr = new PluginCreateRule( Widget.class );
digester.addRule( "root/widget", pcr );
digester.addSetNext( "root/widget", "addChild" );