@Test(expected = BadFetchError.class)
public void testCreateGrammarIllegalParamterCombination()
    throws Exception, BadFetchError {

    final GrammarCreator creator = new DigitsGrammarCreator();
    final URI dtmfUri = new URI(
            "builtin:dtmf/digits?minlength=2;maxlength=4&length=3");
    creator.createGrammar(dtmfUri);
}