if (shapes_and_types == nullptr) return nullptr;

    for (const auto& p : *shapes_and_types) {
      auto* out_shape_and_type = handle_data.add_shape_and_type();
      ic->ShapeHandleToProto(p.shape, out_shape_and_type->mutable_shape());
      out_shape_and_type->set_dtype(p.dtype);
      *out_shape_and_type->mutable_type() = p.type;
    }
  }
  string str_data;
  handle_data.SerializeToString(&str_data);

(And, as you might like to try the thing yourself, some winter
day, I will tell you how the Dodo managed it.)

  First it marked out a race-course, in a sort of circle, (`the
exact shape doesn't matter,' it said,) and then all the party
were placed along the course, here and there.  There was no `One,
two, three, and away,' but they began running when they liked,

(And, as you might like to try the thing yourself, some winter
day, I will tell you how the Dodo managed it.)

  First it marked out a race-course, in a sort of circle, (`the
exact shape doesn't matter,' it said,) and then all the party
were placed along the course, here and there.  There was no `One,
two, three, and away,' but they began running when they liked,