@Test
public void testEquals() throws Exception {

   BooleanExpression expr1 = UnaryExpression.createNOT(SelectorParser.parse("x = 1"));
   BooleanExpression expr2 = UnaryExpression.createNOT(SelectorParser.parse("x = 1"));
   Assert.assertTrue("Created unary expression 1", expr1 instanceof UnaryExpression);
   Assert.assertTrue("Created unary expression 2", expr2 instanceof UnaryExpression);
   Assert.assertEquals("Unary expressions are equal", expr1, expr2);
}