Layer layer = new FeatureLayer(featureSource, style);
map.layers().add(layer);
// Create a JMapFrame with custom toolbar buttons
JMapFrame mapFrame = new JMapFrame(map);
mapFrame.enableToolBar(true);
mapFrame.enableStatusBar(true);
JToolBar toolbar = mapFrame.getToolBar();
toolbar.addSeparator();
toolbar.add(new JButton(new ValidateGeometryAction()));