@Test
public void testAddHavingExpr() throws ParseException {

	solutionModifier.addHaving(new E_Random());
	assertContainsRegex(HAVING + "rand" + OPEN_PAREN + CLOSE_PAREN, query.toString());
	solutionModifier.addHaving("?having2");
	assertContainsRegex(HAVING + "rand" + OPEN_PAREN + CLOSE_PAREN + SPACE + var("having2"), query.toString());
}