@Test
public void testRedecorateTextComponent() {

    JTextField textField = new JTextField();
    AutoCompleteDecorator.decorate(textField, Collections.emptyList(), true);
    
    int expectedFocusListenerLength = textField.getFocusListeners().length;
    
    AutoCompleteDecorator.decorate(textField, Collections.emptyList(), true);
    
    assertThat(textField.getFocusListeners().length, is(expectedFocusListenerLength));
}