assertThat(network.edges()).containsExactly("p", "i", "e").inOrder();
    assertThat(network.nodeOrder()).isEqualTo(unordered());
    assertThat(network.nodes()).containsExactly(4, 1, 3);
  }

  // Sorting of user-defined classes

  @Test
  public void customComparator() {
    Comparator<NonComparableSuperClass> comparator =
        (left, right) -> left.value.compareTo(right.value);

    assertCached(false, 409)
    // the HTTP spec permits caching 410s, but the RI doesn't.
    assertCached(true, 410)
    assertCached(false, 411)
    assertCached(false, 412)
    assertCached(false, 413)
    assertCached(true, 414)
    assertCached(false, 415)
    assertCached(false, 416)
    assertCached(false, 417)
    assertCached(false, 418)
    assertCached(false, 500)
    assertCached(true, 501)