assertThat(network.edgesConnecting(N3, N2)).isEmpty();
  }

  @Test
  public void addEdge_selfLoop_allowed() {
    assume().that(graphIsMutable()).isTrue();
    assume().that(network.allowsSelfLoops()).isTrue();

    assertThat(networkAsMutableNetwork.addEdge(N1, N1, E11)).isTrue();
    assertThat(network.edges()).contains(E11);
    assertThat(network.edgesConnecting(N1, N1)).containsExactly(E11);
  }

  @Test

    assume().that(graph.allowsSelfLoops()).isTrue();

    graphAsMutableGraph.putEdge(N1, N1);
    assertThat(graphAsMutableGraph.putEdge(N1, N1)).isFalse();
  }

  @Test
  public void removeEdge_antiparallelEdges() {
    assume().that(graphIsMutable()).isTrue();

    putEdge(N1, N2);
    putEdge(N2, N1);

    assertThat(graphAsMutableGraph.removeEdge(N1, N2)).isTrue();

    assertThat(future.set(1)).isTrue();
    assertSuccessful(future, 1);
  }

  public void testFailed() throws Exception {
    Exception cause = new Exception();
    assertThat(future.setException(cause)).isTrue();
    assertFailed(future, cause);
  }

  public void testCanceled() throws Exception {
    assertThat(future.cancel(false /* mayInterruptIfRunning */)).isTrue();
    assertCancelled(future, false);
  }

    assertThat(hasCycle(undirectedGraph)).isTrue(); // cyclic in undirected case
  }

  @Test
  public void hasCycle_threeCyclicEdges() {
    for (MutableGraph<Integer> graph : graphsToTest) {
      graph.putEdge(1, 2);
      graph.putEdge(2, 3);
      graph.putEdge(3, 1);
    }
    assertThat(hasCycle(directedGraph)).isTrue();
    assertThat(hasCycle(undirectedGraph)).isTrue();
  }

  @Test

  }

  @Test
  public void addNode_newNode() {
    assume().that(graphIsMutable()).isTrue();

    assertThat(graphAsMutableGraph.addNode(N1)).isTrue();
    assertThat(graph.nodes()).contains(N1);
  }

  @Test
  public void addNode_existingNode() {
    assume().that(graphIsMutable()).isTrue();

    addNode(N1);
    ImmutableSet<Integer> nodes = ImmutableSet.copyOf(graph.nodes());

      return;
    }
    File temp = Files.createTempDir();
    try {
      assertThat(temp.exists()).isTrue();
      assertThat(temp.isDirectory()).isTrue();
      assertThat(temp.listFiles()).isEmpty();
      File child = new File(temp, "child");
      assertThat(child.createNewFile()).isTrue();
      assertThat(child.delete()).isTrue();

      if (!isAndroid() && !isWindows()) {
        PosixFileAttributes attributes =

        assertThat(network.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(network.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractNetworkTest.validateNetwork(network);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(network.removeNode(nodeList.get(i))).isTrue();
      }

        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(graph.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractGraphTest.validateGraph(graph);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

    assertThat(Booleans.asList(ARRAY_TRUE).contains(true)).isTrue();
    assertThat(Booleans.asList(ARRAY_FALSE_TRUE).contains(false)).isTrue();
    assertThat(Booleans.asList(ARRAY_FALSE_TRUE).contains(true)).isTrue();
  }

  public void testAsListEquals() {
    assertThat(Booleans.asList(EMPTY).equals(Collections.emptyList())).isTrue();

    assertThat(Booleans.asList(ARRAY_TRUE).contains(true)).isTrue();
    assertThat(Booleans.asList(ARRAY_FALSE_TRUE).contains(false)).isTrue();
    assertThat(Booleans.asList(ARRAY_FALSE_TRUE).contains(true)).isTrue();
  }

  public void testAsListEquals() {
    assertThat(Booleans.asList(EMPTY).equals(Collections.emptyList())).isTrue();