assertEquals(OPEN, range.lowerBoundType());
    assertTrue(range.hasUpperBound());
    assertEquals(8, (int) range.upperEndpoint());
    assertEquals(OPEN, range.upperBoundType());
    assertFalse(range.isEmpty());
    assertEquals("(4..8)", range.toString());
    reserializeAndAssert(range);
  }

  public void testOpen_invalid() {
    assertThrows(IllegalArgumentException.class, () -> Range.open(4, 3));

    assertThat(recordedRequest.handshakeServerNames).isEmpty()
  }

  /** No SNI for literal IPv4 addresses. */
  @Test
  fun ipv4() {
    val recordedRequest = requestToHostnameViaProxy("76.223.91.57")
    assertThat(recordedRequest.url.host).isEqualTo("76.223.91.57")
    assertThat(recordedRequest.handshakeServerNames).isEmpty()
  }

  @Test
  fun regularHostname() {

    assertTrue(ArbitraryInstances.get(NavigableMap.class).isEmpty());
    assertTrue(ArbitraryInstances.get(LinkedList.class).isEmpty());
    assertTrue(ArbitraryInstances.get(Deque.class).isEmpty());
    assertTrue(ArbitraryInstances.get(Queue.class).isEmpty());
    assertTrue(ArbitraryInstances.get(PriorityQueue.class).isEmpty());
    assertTrue(ArbitraryInstances.get(BitSet.class).isEmpty());

        assertTrue(fieldConfigs.getConfig("test").isEmpty());
    }

    public void test_values() {
        final Map<String, String> params = Maps.of("foo", "bar");
        FieldConfigs fieldConfigs = new FieldConfigs(params);
        assertTrue(fieldConfigs.getConfig("test").isEmpty());
        assertFalse(fieldConfigs.getConfig("foo").isEmpty());

      MutableNetwork<Integer, Object> network =
          networkBuilder.allowsParallelEdges(true).allowsSelfLoops(true).build();

      assertThat(network.nodes()).isEmpty();
      assertThat(network.edges()).isEmpty();
      AbstractNetworkTest.validateNetwork(network);

      while (network.nodes().size() < NUM_NODES) {
        network.addNode(gen.nextInt(NODE_POOL_SIZE));
      }

    for (int trial = 0; trial < NUM_TRIALS; ++trial) {
      MutableGraph<Integer> graph = graphBuilder.allowsSelfLoops(true).build();

      assertThat(graph.nodes()).isEmpty();
      assertThat(graph.edges()).isEmpty();
      AbstractGraphTest.validateGraph(graph);

      while (graph.nodes().size() < NUM_NODES) {
        graph.addNode(gen.nextInt(NODE_POOL_SIZE));
      }

        StringBuilder path = new StringBuilder(128);

        if (!metadata.getGroupId().isEmpty()) {
            path.append(metadata.getGroupId().replace('.', '/')).append('/');

            if (!metadata.getArtifactId().isEmpty()) {
                path.append(metadata.getArtifactId()).append('/');

                if (!metadata.getVersion().isEmpty()) {
                    path.append(metadata.getVersion()).append('/');
                }

    // source node and the second is the target node
    assertThat(network.edgesConnecting(N2, N1)).isEmpty();
  }

  @Test
  public void inEdges_oneEdge() {
    addEdge(N1, N2, E12);
    assertThat(network.inEdges(N2)).containsExactly(E12);
    // Edge direction handled correctly
    assertThat(network.inEdges(N1)).isEmpty();
  }

  @Test
  public void outEdges_oneEdge() {
    addEdge(N1, N2, E12);

    // source node and the second is the target node
    assertThat(network.edgesConnecting(N2, N1)).isEmpty();
  }

  @Test
  public void inEdges_oneEdge() {
    addEdge(N1, N2, E12);
    assertThat(network.inEdges(N2)).containsExactly(E12);
    // Edge direction handled correctly
    assertThat(network.inEdges(N1)).isEmpty();
  }

  @Test
  public void outEdges_oneEdge() {
    addEdge(N1, N2, E12);

  public boolean contains(C value) {
    return rangeContaining(value) != null;
  }

  @Override
  public abstract @Nullable Range<C> rangeContaining(C value);

  @Override
  public boolean isEmpty() {
    return asRanges().isEmpty();
  }

  @Override
  public void add(Range<C> range) {
    throw new UnsupportedOperationException();
  }

  @Override
  public void remove(Range<C> range) {