layout.numColumns = 2;
layout.verticalSpacing = 9;
_panel.setLayout(layout);
setControl(_panel);
((WizardDialog) getWizard().getContainer())
.addPageChangingListener(new IPageChangingListener() {
@Override
public void handlePageChanging(final PageChangingEvent event) {
if (event.getCurrentPage() instanceof DataTypeSelectionPage
&& event.getTargetPage() instanceof DataSelectionPage) {