public void testGetResource_notFound() {
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class, () -> Resources.getResource("no such resource"));
    assertThat(e).hasMessageThat().isEqualTo("resource no such resource not found.");
  }

  public void testGetResource() {
    assertNotNull(Resources.getResource("com/google/common/io/testdata/i18n.txt"));
  }

    assertThat(throwable).isInstanceOf(clazz);
    if (params.length == 1) {
      assertThat(throwable).hasMessageThat().isNull();
    } else if (params.length == 2) {
      assertThat(throwable).hasMessageThat().isEmpty();
    } else {
      assertThat(throwable)
          .hasMessageThat()
          .isEqualTo(Strings.lenientFormat("", Arrays.copyOfRange(params, 2, params.length)));
    }
  }

  /**

        assertThrows(
            IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
    e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

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

    assertThat(throwable).hasMessageThat().startsWith(NODE_STRING);
    assertThat(throwable).hasMessageThat().contains(ERROR_ELEMENT_NOT_IN_GRAPH);
  }
  
  static void assertEdgeNotInGraphErrorMessage(Throwable throwable) {
    assertThat(throwable).hasMessageThat().startsWith(EDGE_STRING);
    assertThat(throwable).hasMessageThat().contains(ERROR_ELEMENT_NOT_IN_GRAPH);
  }

        assertThrows(
            IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
    e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

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

        assertThrows(IllegalArgumentException.class, () -> range.intersection(Range.open(3, 5)));
    assertThat(expected).hasMessageThat().contains("connected");
    expected =
        assertThrows(IllegalArgumentException.class, () -> range.intersection(Range.closed(0, 2)));
    assertThat(expected).hasMessageThat().contains("connected");
  }

  public void testIntersection_deFactoEmpty() {
    {

            IllegalArgumentException.class, () -> graph.edgeValue(EndpointPair.unordered(1, 2)));
    assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH);
    e =
        assertThrows(
            IllegalArgumentException.class, () -> graph.edgeValue(EndpointPair.unordered(2, 1)));
    assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH);
  }

  @Test
  public void edgeValue_undirected_correct() {

            () -> networkAsMutableNetwork.addEdge(N1, N2, EDGE_NOT_IN_GRAPH));
    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
    e =
        assertThrows(
            IllegalArgumentException.class,
            () -> networkAsMutableNetwork.addEdge(N2, N1, EDGE_NOT_IN_GRAPH));
    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
  }

  @Test

            () -> graph.edgeValueOrDefault(EndpointPair.unordered(1, 2), "default"));
    assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH);
    e =
        assertThrows(
            IllegalArgumentException.class,
            () -> graph.edgeValueOrDefault(EndpointPair.unordered(2, 1), "default"));
    assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH);
  }

  @Test

            () -> networkAsMutableNetwork.addEdge(N1, N2, EDGE_NOT_IN_GRAPH));
    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
    e =
        assertThrows(
            IllegalArgumentException.class,
            () -> networkAsMutableNetwork.addEdge(N2, N1, EDGE_NOT_IN_GRAPH));
    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
  }

  @Test