Extracting key-value pair from Produce Request API.

[Chain Head]

Hi,
I am struggling to get the key-value pair from the Produce Request API. I
want to write it to a Buffer for further processing. I can't seem to get
the `k` and `v` values whereas the `.keySize` and `.valueSize` are reported
correctly. Please advise how to extract the key value pairs from the
Produce request API payload.

For better format, see https://pastebin.com/ZKad1ET6

        MemoryRecords partitionRecords = (MemoryRecords)
partitionData.records();
        for (RecordBatch batch : partitionRecords.batches()) {
          // Iterate through reords of a batch
          Buffer batchBuffer = Buffer.buffer();
          Iterator<org.apache.kafka.common.record.Record> it =
batch.iterator();
          while (it.hasNext()) {
            org.apache.kafka.common.record.Record record = it.next();

            String k = "";
            String v = "";

            for (Header header : record.headers()) {
              v = new String(header.value());
              // Some logic with k and v to write to a Buffer
            }

            if (record.hasKey()) {
              ByteBuffer keyBuffer = record.key();
              ByteBuffer valueBuffer = record.value();

              if (record.hasValue()) {
                k = new String(keyBuffer.array(), keyBuffer.position(),
record.keySize());
                v = new String(valueBuffer.array(), valueBuffer.position(),
record.valueSize());
                // Some logic with k and v to write to a Buffer
              } else {
                k = new String(keyBuffer.array(), keyBuffer.position(),
record.keySize());
                // Some logic with k and v to write to a Buffer
              }
            } else {
              // Empty buffer
            }
          }
          }