@Test
public void testLongSerialization() throws Exception {
FunctionIdent fi = new FunctionIdent("collect_set", ImmutableList.<DataType>of(DataTypes.LONG));
AggregationFunction impl = (AggregationFunction) functions.get(fi);
AggregationState state = impl.newState();
BytesStreamOutput streamOutput = new BytesStreamOutput();
state.writeTo(streamOutput);
AggregationState newState = impl.newState();