name_ = std::move(name);
  }

  void set_op(string op) {
    DCHECK(IsEmpty());
    op_ = std::move(op);
  }

  void set_assigned_device(string assigned_device) {
    DCHECK(IsEmpty());
    assigned_device_ = std::move(assigned_device);
  }

  void set_constant_value(Tensor constant_value) {
    DCHECK(IsEmpty());
    constant_value_ = std::move(constant_value);
    op_ = "Const";
  }

                  << node->type_string();
      }
      return false;
    }

    if (assigned_device && node->assigned_device_name() != *assigned_device) {
      if (listener->IsInterested()) {
        *listener << "\nexpected assigned_device " << *assigned_device
                  << " but found \"" << node->assigned_device_name() << "\"";
      }
      return false;
    }

Scope Scope::WithDevice(const string& device) const {
  return Scope(new Impl(*this, Impl::Tags::Device(), device));
}

Scope Scope::WithAssignedDevice(const string& assigned_device) const {
  return Scope(new Impl(*this, Impl::Tags::AssignedDevice(), assigned_device));
}

Scope Scope::WithXlaCluster(const string& xla_cluster) const {
  return Scope(new Impl(*this, Impl::Tags::XlaCluster(), xla_cluster));
}

  Impl(const Scope& other, Tags::Colocate, const Operation& colocate_with_op,
       bool clear_colocations);
  Impl(const Scope& other, Tags::AssignedDevice, const string& assigned_device);
  Impl(const Scope& other, Tags::XlaCluster, const string& xla_cluster);

  std::unordered_set<string> GetColocationConstraints(
      const Operation& colocate_with_op) const;

  Scope WithDevice(const string& device) const;

  /// Returns a new scope.  All ops created within the returned scope will have
  /// their assigned device set to `assigned_device`.
  Scope WithAssignedDevice(const string& assigned_device) const;

  /// Returns a new scope.  All ops created within the returned scope will have
  /// their _XlaCluster attribute set to `xla_cluster`.

      assigned_add.node(),
      NodeWith(AssignedDevice("/job:localhost/replica:0/task:0/device:CPU:0")));
  EXPECT_THAT(unassigned_add.node(), NodeWith(AssignedDevice("")));

  EXPECT_EQ(Explain(unassigned_add.node(),
                    NodeWith(AssignedDevice(
                        "/job:localhost/replica:0/task:0/device:CPU:0"))),
            "\nexpected assigned_device "

  auto m_slice_size_0 = Out(NodeWith(
      Op("Sub"), AssignedDevice(kHostName),
      Inputs(
          Out(NodeWith(Op("Slice"), AssignedDevice(kHostName),
                       Inputs(m_input_shape, Const(zero_64), Const(one_64)))),
          Out(NodeWith(Op("Slice"), AssignedDevice(kHostName),
                       Inputs(m_begin_s64, Const(zero_64), Const(one_64)))))));