composer = new ClassSourceFileComposerFactory(packageName, className);
composer.addImport("com.google.gwt.core.client.GWT");
composer.addImport("java.util.HashMap");
composer.addImport("com.google.gwt.core.client.RunAsyncCallback");
composer.setSuperclass("com.vaadin.terminal.gwt.client.WidgetMap");
SourceWriter sourceWriter = composer.createSourceWriter(context,
printWriter);
Collection<Class<? extends Paintable>> paintablesHavingWidgetAnnotation = getUsedPaintables();
validatePaintables(logger, context, paintablesHavingWidgetAnnotation);