@Test
public void canParseGroupByClause() {

  assertNotNull(parser.parse("SELECT name, AVG(age) FROM test GROUP BY name"));
  assertNotNull(parser.parse("SELECT name AS n, AVG(age) FROM test GROUP BY n"));
  assertNotNull(parser.parse("SELECT ABS(balance) FROM test GROUP BY ABS(balance)"));
  assertNotNull(parser.parse("SELECT ABS(balance) FROM test GROUP BY 1"));
}