presto-main/src/main/java/io/prestosql/util/JsonUtil.java/RealJsonGeneratorWriter/writeJsonValue
class RealJsonGeneratorWriter:        @Override
        public void writeJsonValue(JsonGenerator jsonGenerator, Block block, int position, ConnectorSession session)
                throws IOException
        {
            if (block.isNull(position)) {
                jsonGenerator.writeNull();
            }
            else {
                float value = intBitsToFloat((int) REAL.getLong(block, position));
                jsonGenerator.writeNumber(value);
            }
        }