@Override
		public void add(AbstractButton b) {
			if (b == null) {
				return;
			}
			buttons.addElement(b);

			if (b.isSelected()) {
				if (overriddenSelection == null) {
					overriddenSelection = b.getModel();
				}
				else {
					b.setSelected(false);
				}
			}

			b.getModel().setGroup(this);
		}
SCR 3962 - in this mode we allow the user to press Enter/OK with no text in
the text field, which means to user the current directory as the selected dir
Ghidra/Framework/Docking/src/main/java/docking/widgets/filechooser/GhidraFileChooser.java