null, null, null))
        .addEqualityGroup(
            Tables.<String, @Nullable Object, @Nullable Object>immutableCell("bar", null, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, Integer, @Nullable Object>immutableCell(null, 2, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, @Nullable Object, Character>immutableCell(null, null, 'b'))

        InputStream inputStream = request.getInputStream();
        if (path == null && url == null && reader == null && inputStream == null) {
            throw new IllegalArgumentException("path, url, reader or inputStream must be non null");
        }
        try {
            InputSource source = null;
            if (request.getModelId() != null || request.getLocation() != null) {

   * {@code get(null)}, {@code keySet().contains(null)} or {@code remove(null)}.
   */
  ALLOWS_NULL_KEY_QUERIES,
  ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
  /**
   * The map does not throw {@code NullPointerException} on calls such as {@code
   * containsValue(null)}, {@code values().contains(null)} or {@code values().remove(null)}.
   */
  ALLOWS_NULL_VALUE_QUERIES,

        // v1-->v2
        graph.addEdge(v1, v2, new MetadataGraphEdge("1.1", true, null, null, 2, 1));
        graph.addEdge(v1, v2, new MetadataGraphEdge("1.2", true, null, null, 2, 2));

        // v1-->v3
        graph.addEdge(v1, v3, new MetadataGraphEdge("1.1", true, null, null, 2, 1));
        graph.addEdge(v1, v3, new MetadataGraphEdge("1.2", true, null, null, 4, 2));

        // v3-->v4

    Preconditions.checkNotNull(task, "task must not be null!");
    Preconditions.checkNotNull(result, "result must not be null!");
    return delegate.submit(task, result);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    Preconditions.checkNotNull(task, "task must not be null!");
    return delegate.submit(task);
  }

  @Override
  public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)

        PersistedToolchains global = readToolchains(globalSource, request, problems);

        Source userSource = request.getUserToolchainsSource().orElse(null);
        PersistedToolchains user = readToolchains(userSource, request, problems);

        PersistedToolchains effective = toolchainsMerger.merge(user, global, false, null);

        if (hasErrors(problems)) {

                null, null, null))
        .addEqualityGroup(
            Tables.<String, @Nullable Object, @Nullable Object>immutableCell("bar", null, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, Integer, @Nullable Object>immutableCell(null, 2, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, @Nullable Object, Character>immutableCell(null, null, 'b'))

  private Set<DurationSpec> expireAfterAccesses = Sets.newHashSet((DurationSpec) null);
  private Set<DurationSpec> refreshes = Sets.newHashSet((DurationSpec) null);
  private Set<Strength> keyStrengths = Sets.newHashSet((Strength) null);
  private Set<Strength> valueStrengths = Sets.newHashSet((Strength) null);

  CacheBuilderFactory withConcurrencyLevels(Set<Integer> concurrencyLevels) {

import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUE_QUERIES;
import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;

                qualifier = version;
                majorVersion = null;
                minorVersion = null;
                incrementalVersion = null;
                buildNumber = null;
            }
        }
    }

    private static boolean isDigits(String cs) {
        if (cs == null || cs.isEmpty()) {
            return false;
        }
        final int sz = cs.length();