// fully defined will avoid querying the shapes of the underlying
  // TensorHandles when ParallelTensor::Shape is called. This allows async
  // computation to continue without blocking.
  //
  // The return status and value is the same as `Execute`.
  absl::optional<std::vector<std::unique_ptr<ParallelTensor>>> Join(
      const std::vector<PartialTensorShape>& expected_output_shapes,

    // Target operations
    const TF_Operation* const* target_opers, int ntargets,
    // Output handle
    const char** handle,
    // Output status
    TF_Status*);

// Continue to run the graph with additional feeds and fetches. The
// execution state is uniquely identified by the handle.
TF_CAPI_EXPORT extern void TF_SessionPRun(
    TF_Session*, const char* handle,
    // Input tensors

    if (op_id_it == tensor_tape.end()) {
      continue;
    }
    int64_t op_id = op_id_it->second;
    auto op_it = op_tape->find(op_id);
    auto result_op_it = result.op_tape.find(op_id);
    if (op_id == -1 || op_it == op_tape->end() ||
        result_op_it != result.op_tape.end()) {
      continue;
    }
    CHECK(result.op_tape.emplace(op_id, op_it->second).second);