@Test
public void testCompoundHighlighterAddNull() {

    CompoundHighlighter pipeline = new CompoundHighlighter();
    try {
        pipeline.addHighlighter(null);
        fail("compoundHighlighter must not accept null highlighter");
    } catch(NullPointerException ex) {
        
    }
    ComponentAdapter adapter = createComponentAdapter(allColored, false);
    // was added even with NPE.
    pipeline.highlight(allColored, adapter);
}