panel.add(new Label(getFieldsDescription(service)));
// If a response schema is provided, add a link to the fields editor and
// tell the fields editor about this method's response schema.
if (responseSchema != null && responseSchema.getProperties() != null) {
Label openFieldsEditor = new InlineLabel("Use fields editor");
openFieldsEditor.addStyleName(Resources.INSTANCE.style().clickable());
openFieldsEditor.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
fieldsPopupPanel.show();
fieldsPopupPanel.center();
}