presto-main/src/main/java/io/prestosql/operator/aggregation/DecimalSumAggregation.java/DecimalSumAggregation/outputLongDecimal
class DecimalSumAggregation:    public static void outputLongDecimal(DecimalType type, LongDecimalWithOverflowState state, BlockBuilder out)
    {
        if (state.getLongDecimal() == null) {
            out.appendNull();
        }
        else {
            if (state.getOverflow() != 0) {
                throwOverflowException();
            }
            throwIfOverflows(state.getLongDecimal());
            type.writeSlice(out, state.getLongDecimal());
        }
    }