* // Building a mutable value graph
 * MutableValueGraph<String, Double> graph =
 *     ValueGraphBuilder.undirected().allowsSelfLoops(true).build();
 * graph.putEdgeValue("San Francisco", "San Francisco", 0.0);
 * graph.putEdgeValue("San Jose", "San Jose", 0.0);
 * graph.putEdgeValue("San Francisco", "San Jose", 48.4);
 *
 * // Building an immutable value graph
 * ImmutableValueGraph<String, Double> immutableGraph =

   *     ValueGraphBuilder.undirected()
   *         .<City, Distance>immutable()
   *         .putEdgeValue(PARIS, BERLIN, kilometers(1060))
   *         .putEdgeValue(PARIS, BRUSSELS, kilometers(317))
   *         .putEdgeValue(BERLIN, BRUSSELS, kilometers(764))
   *         .addNode(REYKJAVIK)
   *         .build();
   * }
   *

    ImmutableValueGraph<Integer, String> graph =
        ValueGraphBuilder.directed()
            .<Integer, String>immutable()
            .putEdgeValue(2, 1, "2-1")
            .putEdgeValue(2, 3, "2-3")
            .putEdgeValue(1, 2, "1-2")
            .build();

    assertThat(graph.incidentEdges(2))
        .containsExactly(

   *     ValueGraphBuilder.undirected()
   *         .<City, Distance>immutable()
   *         .putEdgeValue(PARIS, BERLIN, kilometers(1060))
   *         .putEdgeValue(PARIS, BRUSSELS, kilometers(317))
   *         .putEdgeValue(BERLIN, BRUSSELS, kilometers(764))
   *         .addNode(REYKJAVIK)
   *         .build();
   * }
   *