@Test
public void testVar() throws RecognitionException {

  CommonTree sink = FlumeBuilder.parseSink(simple);
  PatternMatch pp = var("top", wild());
  Map<String, CommonTree> m = pp.match(sink);
  assertNotNull(m);
  assertNotNull(m.get("top"));
  dumpMatches(m);
  LOG.info(m);
}