@Test
public void t02_defaultGrouping() throws Exception {

    String e1 = "tagA and not tagB or tagC";
    assertEquals("or(tagC, and(tagA, not tagB))", parser.parse(e1));
    String e2 = "not tagA and tagB or tagC";
    assertEquals("or(tagC, and(tagB, not tagA))", parser.parse(e2));
    String e3 = "not tagA or tagB and tagC";
    assertEquals("and(tagC, or(tagB, not tagA))", parser.parse(e3));
}