private ComboBoxModel<String> getModel() {
		BookmarkManager mgr = program.getBookmarkManager();
		String[] categories = mgr.getCategories(BookmarkType.NOTE);
		String[] array = new String[categories.length + 1];
		array[0] = "";
		System.arraycopy(categories, 0, array, 1, categories.length);
		Arrays.sort(array);
		return new DefaultComboBoxModel<>(array);
	}
Returns a ComboBoxModel populated with a sorted unique list
of all currently defined Bookmark categories.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/bookmark/CreateBookmarkDialog.java