private final boolean allowsSelfLoops;
  private final ElementOrder<N> nodeOrder;
  private final ElementOrder<E> edgeOrder;

  final MapIteratorCache<N, NetworkConnections<N, E>> nodeConnections;

  // We could make this a Map<E, EndpointPair<N>>. It would make incidentNodes(edge) slightly
  // faster, but also make Networks consume 5 to 20+% (increasing with average degree) more memory.

        == createInstance(factory, args).hashCode();
  }

  // distinctValues is a type-safe class-values mapping, but we don't have a type-safe data
  // structure to hold the mappings.
  @SuppressWarnings({"unchecked", "rawtypes"})
  private FreshValueGenerator newFreshValueGenerator() {
    FreshValueGenerator generator =
        new FreshValueGenerator() {
          @Override