private String checkResponseBody(String causeMessage) throws IOException {
    return body().orElseThrow(() -> {
      final String causeWithContext = String.format("HTTP response-body unexpectedly empty: %s", causeMessage);
      if (bodyException().isPresent()) {
        return toIoException(causeWithContext, bodyException().get());
      } else {
        return toIoException(causeWithContext);
      }
    });
  }
Returns response body or throws DTP base exception with `causeMessage`.
extensions/data-transfer/portability-data-transfer-microsoft/src/main/java/org/datatransferproject/transfer/microsoft/MicrosoftApiResponse.java