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