assertThat(dim1 * dim2).isAtLeast(0);
    testConcatOverflow(dim1, dim2);
  }

  private static void testConcatOverflow(int arraysDim1, int arraysDim2) {
    assertThat((long) arraysDim1 * arraysDim2).isNotEqualTo((long) (arraysDim1 * arraysDim2));

    char[][] arrays = new char[arraysDim1][];
    // it's shared to avoid using too much memory in tests
    char[] sharedArray = new char[arraysDim2];

    Files.setLastModifiedTime(temp, FileTime.fromMillis(0));
    assertEquals(0, Files.getLastModifiedTime(temp).toMillis());
    MoreFiles.touch(temp);
    assertThat(Files.getLastModifiedTime(temp).toMillis()).isNotEqualTo(0);
  }

  public void testCreateParentDirectories_root() throws IOException {
    // We use a fake filesystem to sidestep flaky problems with Windows (b/136041958).

    assertThat(dim1 * dim2).isAtLeast(0);
    testConcatOverflow(dim1, dim2);
  }

  private static void testConcatOverflow(int arraysDim1, int arraysDim2) {
    assertThat((long) arraysDim1 * arraysDim2).isNotEqualTo((long) (arraysDim1 * arraysDim2));

    double[][] arrays = new double[arraysDim1][];
    // it's shared to avoid using too much memory in tests
    double[] sharedArray = new double[arraysDim2];

    otherGraph.putEdgeValue(1, 2, "valueA");
    assertThat(graph).isEqualTo(otherGraph);

    otherGraph.putEdgeValue(1, 2, "valueB");
    assertThat(graph).isNotEqualTo(otherGraph); // values differ
  }

  @Test
  public void incidentEdges_stableIncidentEdgeOrder_preservesIncidentEdgesOrder_directed() {

    Files.setLastModifiedTime(temp, FileTime.fromMillis(0));
    assertEquals(0, Files.getLastModifiedTime(temp).toMillis());
    MoreFiles.touch(temp);
    assertThat(Files.getLastModifiedTime(temp).toMillis()).isNotEqualTo(0);
  }

  public void testCreateParentDirectories_root() throws IOException {
    // We use a fake filesystem to sidestep flaky problems with Windows (b/136041958).

      }

      for (N adjacentNode : sanityCheckSet(graph.adjacentNodes(node))) {
        if (!graph.allowsSelfLoops()) {
          assertThat(node).isNotEqualTo(adjacentNode);
        }
        assertThat(
                graph.predecessors(node).contains(adjacentNode)
                    || graph.successors(node).contains(adjacentNode))
            .isTrue();
      }

    assertThat(expected).hasMessageThat().matches(pattern);
      Matcher matcher = pattern.matcher(expected.getMessage());
      assertThat(matcher.matches()).isTrue();
      assertThat(matcher.group(1)).isNotEqualTo(matcher.group(2));
  }

  public void testOf() {
    assertMapEquals(ImmutableMap.of("one", 1), "one", 1);
    assertMapEquals(ImmutableMap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMapEquals(

    otherGraph.putEdgeValue(1, 2, "valueA");
    assertThat(graph).isEqualTo(otherGraph);

    otherGraph.putEdgeValue(1, 2, "valueB");
    assertThat(graph).isNotEqualTo(otherGraph); // values differ
  }

  @Test
  public void incidentEdges_stableIncidentEdgeOrder_preservesIncidentEdgesOrder_directed() {

    assertThat(expected).hasMessageThat().matches(pattern);
      Matcher matcher = pattern.matcher(expected.getMessage());
      assertThat(matcher.matches()).isTrue();
      assertThat(matcher.group(1)).isNotEqualTo(matcher.group(2));
  }

  public void testOf() {
    assertMapEquals(ImmutableMap.of("one", 1), "one", 1);
    assertMapEquals(ImmutableMap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMapEquals(

    assertThat(dim1 * dim2).isAtLeast(0);
    testConcatOverflow(dim1, dim2);
  }

  private static void testConcatOverflow(int arraysDim1, int arraysDim2) {
    assertThat((long) arraysDim1 * arraysDim2).isNotEqualTo((long) (arraysDim1 * arraysDim2));

    boolean[][] arrays = new boolean[arraysDim1][];
    // it's shared to avoid using too much memory in tests
    boolean[] sharedArray = new boolean[arraysDim2];