// Build 2nd Matrix.
  float vals2[] = {5.0f, 6.0f, 7.0f, 8.0f};
  TFE_TensorHandle* t2 =
      TestMatrixTensorHandleWithInput(eager_ctx, vals2, dims, num_dims);

  TF_AbstractTensor* at2 = TF_CreateAbstractTensorFromEagerTensor(
      t2, status.get());  // get abstract tensor
  ASSERT_EQ(TF_OK, TF_GetCode(status.get())) << TF_Message(status.get());

  // Build an abstract operation.

  }

  // use an enum to get easy serializability
  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

    CharAtFunction(int index) {
      this.index = index;
    }

    @Override

  }

  // use an enum to get easy serializability
  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

    CharAtFunction(int index) {
      this.index = index;
    }

    @Override