@Test
public void testZoomableKeepsMonthStringBackground() {

    JXMonthView monthView = new JXMonthView();
    monthView.setZoomable(true);
    assertEquals(monthView.getMonthStringBackground(), 
            ((BasicMonthViewUI) monthView.getUI()).getCalendarHeaderHandler().getHeaderComponent().getBackground());
    SwingUtilities.updateComponentTreeUI(monthView);
    assertEquals(monthView.getMonthStringBackground(), 
            ((BasicMonthViewUI) monthView.getUI()).getCalendarHeaderHandler().getHeaderComponent().getBackground());
}