InternalCallVerifier BooleanVerifier AssumptionSetter EqualityVerifier HybridVerifier 

@Test public void trackAndUntrackColumn(){
  assumeTrue(tracker.getTrackedColumns().isEmpty());
  tracker.trackColumn(0);
  Set expected=new HashSet();
  expected.add(0);
  assertEquals(expected,tracker.getTrackedColumns());
  tracker.untrackColumn(0);
  assertTrue(tracker.getTrackedColumns().isEmpty());
}