View switcherView = SwitcherView.VIEW_INFO.createView(mockComponent);
// Find combo box so we can test its UI object
@SuppressWarnings("rawtypes")
JComboBox comboBox = findComponent(switcherView, JComboBox.class);
ComboBoxUI ui = comboBox.getUI();
// Verify that ui paints a rounded rect (per spec)
Graphics mockGraphics = Mockito.mock(Graphics.class, Mockito.RETURNS_MOCKS);
ui.paint(mockGraphics, comboBox);
Mockito.verify(mockGraphics).fillRoundRect(
Mockito.anyInt(), Mockito.anyInt(), Mockito.anyInt(),Mockito.anyInt(),Mockito.anyInt(),Mockito.anyInt());
}