@Override
 public String toString() {
   StringBuilder str = new StringBuilder();
   str.append(getNameString()).append(" for ").append(object);
   if (unknownFields != null) {
     str.append(" with unknown fields ").append(unknownFields.asMap().keySet());
   }
   return str.toString();
 }
  /**
   * Converts a protobuf message to an SDC Record Field.
   *
   * @param record SDC Record to add field to
   * @param fieldPath location in record where to insert field.
   * @param descriptor protobuf descriptor instance
   * @param messageTypeToExtensionMap protobuf extensions map
   * @param message message to decode and insert into the specified field path
   * @return new Field instance representing the decoded message
   * @throws DataParserException
   */
  public static Field protobufToSdcField(
      Record record,
      String fieldPath,
      Descriptors.Descriptor descriptor,
      Map<String, Set<Descriptors.FieldDescriptor>> messageTypeToExtensionMap,
      Object message)
      throws DataParserException {
    Map<String, Field> sdcRecordMapFieldValue = new HashMap<>();

    // get all the expected fields from the proto file
    Map<String, Descriptors.FieldDescriptor> protobufFields = new LinkedHashMap<>();
    for (Descriptors.FieldDescriptor fieldDescriptor : descriptor.getFields()) {
      protobufFields.put(fieldDescriptor.getName(), fieldDescriptor);
    }

    // get all fields in the read message
    Map<Descriptors.FieldDescriptor, Object> values = ((DynamicMessage) message).getAllFields();

    // for every field present in the proto definition create an sdc field.
    for (Descriptors.FieldDescriptor fieldDescriptor : protobufFields.values()) {
      Object value = values.get(fieldDescriptor);
      sdcRecordMapFieldValue.put(
          fieldDescriptor.getName(),
          createField(record, fieldPath, fieldDescriptor, messageTypeToExtensionMap, value));
    }

    // handle applicable extensions for this message type
    if (messageTypeToExtensionMap.containsKey(descriptor.getFullName())) {
      for (Descriptors.FieldDescriptor fieldDescriptor :
          messageTypeToExtensionMap.get(descriptor.getFullName())) {
        if (values.containsKey(fieldDescriptor)) {
          Object value = values.get(fieldDescriptor);
          sdcRecordMapFieldValue.put(
              fieldDescriptor.getName(),
              createField(record, fieldPath, fieldDescriptor, messageTypeToExtensionMap, value));
        }
      }
    }

    // handle unknown fields
    // unknown fields can go into the record header
    UnknownFieldSet unknownFields = ((DynamicMessage) message).getUnknownFields();
    if (!unknownFields.asMap().isEmpty()) {
      ByteArrayOutputStream bOut = new ByteArrayOutputStream();
      try {
        unknownFields.writeDelimitedTo(bOut);
        bOut.flush();
        bOut.close();
      } catch (IOException e) {
        throw new DataParserException(Errors.PROTOBUF_10, e.toString(), e);
      }
      String path = fieldPath.isEmpty() ? FORWARD_SLASH : fieldPath;
      byte[] bytes = org.apache.commons.codec.binary.Base64.encodeBase64(bOut.toByteArray());
      record
          .getHeader()
          .setAttribute(
              PROTOBUF_UNKNOWN_FIELDS_PREFIX + path, new String(bytes, StandardCharsets.UTF_8));
    }

    return Field.create(sdcRecordMapFieldValue);
  }