code: @Override
    public ScanHandler readFlatRows(ReadRowsRequest request, StreamObserver<FlatRow> observer) {
      if (shouldOverrideAppProfile(request.getAppProfileId())) {
        request = request.toBuilder().setAppProfileId(clientDefaultAppProfileId).build();
      }
  
      RetryingReadRowsOperation operation = createReadRowsRetryListener(request, observer);
  
      // Start the operation.
      operation.getAsyncResult();
  
      return operation;
    }
docs: {@inheritDoc}