.edgeOrder(network.edgeOrder());
  }

  /**
   * Returns an {@link ImmutableNetwork.Builder} with the properties of this {@link NetworkBuilder}.
   *
   * <p>The returned builder can be used for populating an {@link ImmutableNetwork}.
   *
   * @since 28.0
   */
  public <N1 extends N, E1 extends E> ImmutableNetwork.Builder<N1, E1> immutable() {
    NetworkBuilder<N1, E1> castBuilder = cast();