{
StateCompiler compiler = new StateCompiler();
AccumulatorStateFactory<VarianceState> factory = compiler.generateStateFactory(VarianceState.class);
AccumulatorStateSerializer<VarianceState> serializer = compiler.generateStateSerializer(VarianceState.class);
VarianceState singleState = factory.createSingleState();
VarianceState deserializedState = factory.createSingleState();
singleState.setMean(1);
singleState.setCount(2);
singleState.setM2(3);
BlockBuilder builder = VarcharType.VARCHAR.createBlockBuilder(new BlockBuilderStatus());
serializer.serialize(singleState, builder);
Block block = builder.build();
serializer.deserialize(block, 0, deserializedState);
assertEquals(deserializedState.getCount(), singleState.getCount());
assertEquals(deserializedState.getMean(), singleState.getMean());
assertEquals(deserializedState.getM2(), singleState.getM2());
}