absl::Status AddInputList(AbstractOperation*,
                          absl::Span<AbstractTensorHandle* const> inputs,
                          ForwardOperation*);

// Sets the attrs in the `ForwardOperation`.
absl::Status SetAttrString(AbstractOperation*, const char* attr_name,
                           const char* data, size_t length, ForwardOperation*);
absl::Status SetAttrInt(AbstractOperation*, const char* attr_name,

    ASSERT_EQ(errors::OK, s.code()) << s.message();
  }
  s = AddInput(check_numerics_op.get(), t.get(), &forward_op);
  ASSERT_EQ(errors::OK, s.code()) << s.message();
  string message = "This is the way!";
  s = SetAttrString(check_numerics_op.get(), "message", message.data(),
                    message.length(), &forward_op);
  ASSERT_EQ(errors::OK, s.code()) << s.message();
  int num_retvals = 1;

      absl::Span<AbstractTensorHandle* const> inputs) = 0;
  virtual absl::Status Execute(absl::Span<AbstractTensorHandle*> retvals,
                               int* num_retvals) = 0;

  virtual absl::Status SetAttrString(const char* attr_name, const char* data,
                                     size_t length) = 0;
  virtual absl::Status SetAttrInt(const char* attr_name, int64_t value) = 0;