AggregateAvgFilter extends AggregateAvg { public IAggregate cloneAggregate() { return new AggregateAvgFilter(getValueType()); } AggregateAvgFilter(Class< ? > type); IAggregate cloneAggregate();  }
@Test public void testCloneAggregate() { agg = new AggregateAvgFilter(Double.class); assertEquals(Double.class, agg.cloneAggregate().getValueType()); assertEquals(true, agg.cloneAggregate() instanceof AggregateAvgFilter); }