this.isDirected = builder.directed;
    this.allowsParallelEdges = builder.allowsParallelEdges;
    this.allowsSelfLoops = builder.allowsSelfLoops;
    this.nodeOrder = builder.nodeOrder.cast();
    this.edgeOrder = builder.edgeOrder.cast();
    // Prefer the heavier "MapRetrievalCache" for nodes if lookup is expensive. This optimizes
    // methods that access the same node(s) repeatedly, such as Graphs.removeEdgesConnecting().

  //

  /** Returns all nodes in this network, in the order specified by {@link #nodeOrder()}. */
  Set<N> nodes();

  /** Returns all edges in this network, in the order specified by {@link #edgeOrder()}. */
  Set<E> edges();

  /**
   * Returns a live view of this network as a {@link Graph}. The resulting {@link Graph} will have

  //

  /** Returns all nodes in this network, in the order specified by {@link #nodeOrder()}. */
  Set<N> nodes();

  /** Returns all edges in this network, in the order specified by {@link #edgeOrder()}. */
  Set<E> edges();

  /**
   * Returns a live view of this network as a {@link Graph}. The resulting {@link Graph} will have