@Test
public void testVisitUnaryExpressionOperation() {

	TermFilter termFilter = new TermFilter("title", "title1");
	BooleanFilter booleanFilter =
		(BooleanFilter)_expressionVisitorImpl.visitUnaryExpressionOperation(
			UnaryExpression.Operation.NOT, termFilter);
	Assert.assertTrue(booleanFilter.hasClauses());
	List<BooleanClause<Filter>> booleanClauses =
		booleanFilter.getMustNotBooleanClauses();
	Assert.assertEquals(
		booleanClauses.toString(), 1, booleanClauses.size());
	BooleanClause<Filter> queryBooleanClause = booleanClauses.get(0);
	Assert.assertEquals(termFilter, queryBooleanClause.getClause());
	Assert.assertEquals(
		BooleanClauseOccur.MUST_NOT,
		queryBooleanClause.getBooleanClauseOccur());
}