*
   * <p>For all multimaps generated by the resulting builder, the {@link Multimap#keySet()} can be
   * safely cast to a {@link java.util.SortedSet}, and the {@link Multimap#asMap()} can safely be
   * cast to a {@link java.util.SortedMap}.
   */
  @SuppressWarnings("rawtypes")
  public static MultimapBuilderWithKeys<Comparable> treeKeys() {
    return treeKeys(Ordering.natural());

    Throwable error = null;
    if (isDone()) {
      return;
    }
    try {
      result = runInterruptibly();
    } catch (Throwable t) {
      error = t;
    }
    if (error == null) {
      // The cast is safe because of the `run` and `error` checks.
      afterRanInterruptiblySuccess(uncheckedCastNullableTToT(result));
    } else {
      afterRanInterruptiblyFailure(error);
    }
  }

  abstract boolean isDone();

    this.isDirected = builder.directed;
    this.allowsParallelEdges = builder.allowsParallelEdges;
    this.allowsSelfLoops = builder.allowsSelfLoops;
    this.nodeOrder = builder.nodeOrder.cast();
    this.edgeOrder = builder.edgeOrder.cast();
    // Prefer the heavier "MapRetrievalCache" for nodes if lookup is expensive. This optimizes
    // methods that access the same node(s) repeatedly, such as Graphs.removeEdgesConnecting().

    this.isDirected = builder.directed;
    this.allowsParallelEdges = builder.allowsParallelEdges;
    this.allowsSelfLoops = builder.allowsSelfLoops;
    this.nodeOrder = builder.nodeOrder.cast();
    this.edgeOrder = builder.edgeOrder.cast();
    // Prefer the heavier "MapRetrievalCache" for nodes if lookup is expensive. This optimizes
    // methods that access the same node(s) repeatedly, such as Graphs.removeEdgesConnecting().

    }
    Class<? extends T> implementation = getImplementation(type);
    if (implementation != null) {
      return get(implementation);
    }
    if (type == Stream.class) {
      return type.cast(Stream.empty());
    }
    if (type.isEnum()) {
      T[] enumConstants = type.getEnumConstants();
      return (enumConstants == null || enumConstants.length == 0) ? null : enumConstants[0];
    }

  @Override
  @CheckForNull
  public V get(@CheckForNull Object key) {
    Object result =
        RegularImmutableMap.get(keyHashTable, alternatingKeysAndValues, size, keyOffset, key);
    /*
     * We can't simply cast the result of `RegularImmutableMap.get` to V because of a bug in our
     * nullness checker (resulting from https://github.com/jspecify/checker-framework/issues/8).
     */
    if (result == null) {
      return null;

  private transient int[] nextInBucketVToK;
  /** The "entry" of the first element in insertion order. */
  private transient int firstInInsertionOrder;
  /** The "entry" of the last element in insertion order. */
  private transient int lastInInsertionOrder;
  /** Maps an "entry" to the "entry" that precedes it in insertion order. */
  private transient int[] prevInInsertionOrder;

        this.objects = objects;
    }

    @Override
    public <T> T lookup(Class<T> type) {
        return objects.stream()
                .filter(type::isInstance)
                .map(type::cast)
                .findAny()
                .orElseThrow(() -> new LookupException("No service of type " + type));
    }

    @Override
    public <T> T lookup(Class<T> type, String name) {
        return null;

        /*
         * We have an Iterator<E> and want to cast it to MultiExceptionListIterator. Because we're
         * inside an AbstractIteratorTester<E>, that's implicitly a cast to
         * AbstractIteratorTester<E>.MultiExceptionListIterator. The runtime won't be able to verify
         * the AbstractIteratorTester<E> part, so it's an unchecked cast. We know, however, that the

   */
  @SuppressWarnings("nullness")
  @ParametricNullness
  static <T extends @Nullable Object> T uncheckedCastNullableTToT(@CheckForNull T t) {
    return t;
  }

  /**
   * Returns {@code null} cast to any type.
   *
   * <p>This method is intended to help with usages of type parameters that have {@linkplain
   * ParametricNullness parametric nullness}. Sometimes, code may receive a null {@code T} but store