How to add Combo (SWT) to my NormalizationNodeDialog?

I decided to try to create my own node on Java language. I don’t understand how to properly add Combo (SWT) to my NormalizationNodeDialog.

Add this:

Display display = new Display();

Shell shell = new Shell(display);

RowLayout rowLayout = new RowLayout();

rowLayout.marginLeft = 10;

rowLayout.marginTop = 10;

shell.setLayout(rowLayout);

Label label = new Label(shell,SWT.NONE );

label.setText(“Select language:”);

Combo combo = new Combo(shell, SWT.DROP_DOWN);

String[ ] items = new String[ ] { “English”, “Vietnamese” };

combo.setItems(items);

Add here:

public class NormalizationNodeDialog extends DefaultNodeSettingsPane {

protected NormalizationNodeDialog() {

super();

…

}

}

Please, help me.