int expected_max_outputs,
                    CancellationManager& cancellation_manager,
                    std::optional<int64_t> step_id = std::nullopt) const;

  // Blocks until the previous `StartExecute` has run `TFE_Execute` on each
  // device. If is_async=false (constructor argument) this means the ops have
  // run and have results. If is_async=true it means that all of the