presto-main/src/main/java/io/prestosql/operator/aggregation/RealSumAggregation.java/RealSumAggregation/output
class RealSumAggregation:    @OutputFunction(StandardTypes.REAL)
    public static void output(@AggregationState NullableDoubleState state, BlockBuilder out)
    {
        if (state.isNull()) {
            out.appendNull();
        }
        else {
            REAL.writeLong(out, floatToRawIntBits((float) state.getDouble()));
        }
    }