*   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 *   <li>graphs whose edges have associated values
 * </ul>
 *
 * <p>{@code ValueGraph}, as a subtype of {@code Graph}, explicitly does not support parallel edges,
 * and forbids implementations or extensions with parallel edges. If you need parallel edges, use
 * {@link Network}. (You can use a positive {@code Integer} edge value as a loose representation of

          assertThat(graph.hasEdgeConnecting(endpoints.nodeU(), endpoints.nodeV())).isTrue();
        }
      }
    }

    sanityCheckSet(graph.edges());
    assertThat(graph.edges()).doesNotContain(EndpointPair.of(graph, new Object(), new Object()));
    assertThat(graph.edges()).isEqualTo(allEndpointPairs);
  }

  /**
   * Verifies that the {@code Set} returned by {@code nodes} has the expected mutability property

        while (resultWithDoubleSelfLoop.hasNext()) {
          EndpointPair<N> edge = resultWithDoubleSelfLoop.next();
          if (edge.nodeU().equals(edge.nodeV())) {
            if (!alreadySeenSelfLoop.getAndSet(true)) {
              return edge;
            }
          } else {
            return edge;
          }
        }
        return endOfData();
      }
    };
  }

          "stanford.edu",
          "state.ca.us",
          "www.state.ca.us",
          "state.ca.us",
          "pvt.k12.ca.us",
          "www.rave.ca.",
          "cnn.ca",
          "ledger-enquirer.com",
          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",

        ComparableVersion version2 = new ComparableVersion("0.2");
        assertEquals("0.2", version2.getCanonical());
    }

    /**
     * Test <a href="https://issues.apache.org/jira/browse/MNG-5568">MNG-5568</a> edge case
     * which was showing transitive inconsistency: since A &gt; B and B &gt; C then we should have A &gt; C
     * otherwise sorting a list of ComparableVersions() will in some cases throw runtime exception;

  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

    @Override
    public String toString() {
      return "Functions.toStringFunction()";
    }
  }

  /**
   * Returns the identity function.
   *

  }

  private static <K, V> ImmutableSetMultimap<K, V> copyOf(
      Multimap<? extends K, ? extends V> multimap,
      @CheckForNull Comparator<? super V> valueComparator) {
    checkNotNull(multimap); // eager for GWT
    if (multimap.isEmpty() && valueComparator == null) {
      return of();
    }

    if (multimap instanceof ImmutableSetMultimap) {

 *       locks---to each of the acquired locks, an edge from the soon-to-be-acquired lock is either
 *       verified or created.
 *   <li>If a new edge needs to be created, the outgoing edges of the acquired locks are traversed
 *       to check for a cycle that reaches the lock to be acquired. If no cycle is detected, a new
 *       "safe" edge is created.
 *   <li>If a cycle is detected, an "unsafe" (cyclic) edge is created to represent a potential

    Graph<Integer> asGraph = graph.asGraph();
    AbstractGraphTest.validateGraph(asGraph);
    assertThat(graph.nodes()).isEqualTo(asGraph.nodes());
    assertThat(graph.edges()).isEqualTo(asGraph.edges());
    assertThat(graph.nodeOrder()).isEqualTo(asGraph.nodeOrder());
    assertThat(graph.incidentEdgeOrder()).isEqualTo(asGraph.incidentEdgeOrder());
    assertThat(graph.isDirected()).isEqualTo(asGraph.isDirected());

          "stanford.edu",
          "state.ca.us",
          "www.state.ca.us",
          "state.ca.us",
          "pvt.k12.ca.us",
          "www.rave.ca.",
          "cnn.ca",
          "ledger-enquirer.com",
          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",