int num_retvals = 1;
  TFE_Execute(matmul, &retvals[0], &num_retvals, status);
  TFE_DeleteOp(matmul);
  if (!async) {
    EXPECT_NE(TF_OK, TF_GetCode(status));
  } else {
    TF_Tensor* t = TFE_TensorHandleResolve(retvals[0], status);
    EXPECT_NE(TF_OK, TF_GetCode(status));
    EXPECT_EQ(nullptr, t);
    const char* msg = "Matrix size-incompatible: In[0]: [2,2], In[1]: [3,2]";

  TF_Tensor* a =
      TF_AllocateTensor(TF_UINT64, dims, 2, 6 * TF_DataTypeSize(TF_UINT64));
  TF_Tensor* b =
      TF_AllocateTensor(TF_UINT64, nullptr, 0, TF_DataTypeSize(TF_UINT64));
  EXPECT_NE(a, nullptr);
  EXPECT_NE(b, nullptr);

  EXPECT_EQ(6, TF_TensorElementCount(a));
  EXPECT_EQ(1, TF_TensorElementCount(b));
  EXPECT_EQ(6 * TF_DataTypeSize(TF_UINT64), TF_TensorByteSize(a));