presto-iceberg/src/main/java/io/prestosql/plugin/iceberg/PartitionData.java/PartitionData/toJson
class PartitionData:    public String toJson()
    {
        try {
            StringWriter writer = new StringWriter();
            JsonGenerator generator = FACTORY.createGenerator(writer);
            generator.writeStartObject();
            generator.writeArrayFieldStart(PARTITION_VALUES_FIELD);
            for (Object value : partitionValues) {
                generator.writeObject(value);
            }
            generator.writeEndArray();
            generator.writeEndObject();
            generator.flush();
            return writer.toString();
        }
        catch (IOException e) {
            throw new UncheckedIOException("JSON conversion failed for PartitionData: " + Arrays.toString(partitionValues), e);
        }
    }