How to use the rsocket-core.UTF8Encoder.encode function in rsocket-core

SERVICE_LENGTH_SIZE +
      serviceLength +
      METHOD_LENGTH_SIZE +
      methodLength +
      TRACING_LENGTH_SIZE +
      tracingLength +
      metadataLength,
  );

  let offset = buffer.writeUInt16BE(VERSION, 0);

  offset = buffer.writeUInt16BE(serviceLength, offset);
  offset = UTF8Encoder.encode(service, buffer, offset, offset + serviceLength);

  offset = buffer.writeUInt16BE(methodLength, offset);
  offset = UTF8Encoder.encode(method, buffer, offset, offset + methodLength);

  offset = buffer.writeUInt16BE(tracingLength, offset);
  offset = BufferEncoder.encode(
    tracing,
    buffer,
    offset,
    offset + tracingLength,
  );

  BufferEncoder.encode(metadata, buffer, offset, offset + metadataLength);

  return buffer;
}

const buffer = createBuffer(
    VERSION_SIZE +
      SERVICE_LENGTH_SIZE +
      serviceLength +
      METHOD_LENGTH_SIZE +
      methodLength +
      TRACING_LENGTH_SIZE +
      tracingLength +
      metadataLength,
  );

  let offset = buffer.writeUInt16BE(VERSION, 0);

  offset = buffer.writeUInt16BE(serviceLength, offset);
  offset = UTF8Encoder.encode(service, buffer, offset, offset + serviceLength);

  offset = buffer.writeUInt16BE(methodLength, offset);
  offset = UTF8Encoder.encode(method, buffer, offset, offset + methodLength);

  offset = buffer.writeUInt16BE(tracingLength, offset);
  offset = BufferEncoder.encode(
    tracing,
    buffer,
    offset,
    offset + tracingLength,
  );

  BufferEncoder.encode(metadata, buffer, offset, offset + metadataLength);

  return buffer;
}

(aggregate, key) => {
      const val = map[key];
      const keyLen = UTF8Encoder.byteLength(key);
      const keyBuf = createBuffer(keyLen);
      UTF8Encoder.encode(key, keyBuf, 0, keyLen);

      const valLen = UTF8Encoder.byteLength(val);
      const valBuf = createBuffer(valLen);
      UTF8Encoder.encode(val, valBuf, 0, valLen);

      const newEntries = aggregate.entries;
      newEntries.push({keyLen, keyBuf, valLen, valBuf});

      return {
        //4 for the sizes plus the actual key and actual value
        totalSize: aggregate.totalSize + 4 + keyLen + valLen,
        entries: newEntries,
      };
    },
    {totalSize: 0, entries: []},

(aggregate, key) => {
      const val = map[key];
      const keyLen = UTF8Encoder.byteLength(key);
      const keyBuf = createBuffer(keyLen);
      UTF8Encoder.encode(key, keyBuf, 0, keyLen);

      const valLen = UTF8Encoder.byteLength(val);
      const valBuf = createBuffer(valLen);
      UTF8Encoder.encode(val, valBuf, 0, valLen);

      const newEntries = aggregate.entries;
      newEntries.push({keyLen, keyBuf, valLen, valBuf});

      return {
        //4 for the sizes plus the actual key and actual value
        totalSize: aggregate.totalSize + 4 + keyLen + valLen,
        entries: newEntries,
      };
    },
    {totalSize: 0, entries: []},