companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {
      override fun lookup(hostname: String): List<InetAddress> {
        try {

      Iterable<? extends Entry<? extends K, ? extends V>> entries) {
    return new Builder<K, V>().putAll(entries).build();
  }

  ImmutableBiMap(Map<K, V> delegate) {
    super(delegate);
  }

  public abstract ImmutableBiMap<V, K> inverse();

  @Override
  public ImmutableSet<V> values() {
    return inverse().keySet();
  }

  @CheckForNull

 *   <li>{@link UnmodifiableIterator}
 *   <li>{@link UnmodifiableListIterator}
 * </ul>
 *
 * <h2>Forwarding collections</h2>
 *
 * We provide implementations of collections that forward all method calls to a delegate collection
 * by default. Subclasses can override one or more methods to implement the decorator pattern. For
 * an example, see {@link ForwardingCollection}.
 *
 * <h2>Other</h2>
 *
 * <ul>

 *   <li>{@link UnmodifiableIterator}
 *   <li>{@link UnmodifiableListIterator}
 * </ul>
 *
 * <h2>Forwarding collections</h2>
 *
 * We provide implementations of collections that forward all method calls to a delegate collection
 * by default. Subclasses can override one or more methods to implement the decorator pattern. For
 * an example, see {@link ForwardingCollection}.
 *
 * <h2>Other</h2>
 *
 * <ul>

  // description of the mutation suitable for returning to the user.
  //
  // Sessions are added to this map in TF_NewSession, and removed in
  // TF_DeleteSession.
  // TF_Graph may only / must be deleted when
  //   sessions.size() == 0 && delete_requested == true
  //
  // TODO(b/74949947): mutations currently trigger a warning instead of a bad
  // status, this should be reverted when possible.

  }

  public void testPadEnd_null() {
    assertThrows(NullPointerException.class, () -> Strings.padEnd(null, 5, '0'));
  }

  @SuppressWarnings("InlineMeInliner") // test of method that doesn't just delegate
  public void testRepeat() {
    String input = "20";
    assertEquals("", Strings.repeat(input, 0));
    assertEquals("20", Strings.repeat(input, 1));
    assertEquals("2020", Strings.repeat(input, 2));

    return forwardMultiset().headMultiset(fromElement, boundType).descendingMultiset();
  }

  @Override
  protected Multiset<E> delegate() {
    return forwardMultiset();
  }

  @Override
  public SortedMultiset<E> descendingMultiset() {
    return forwardMultiset();
  }

  @Override
  @CheckForNull

      this.concurrencyLevel = concurrencyLevel;
      this.delegate = delegate;
    }

    @Override
    protected ConcurrentMap<K, V> delegate() {
      return delegate;
    }

    void writeMapTo(ObjectOutputStream out) throws IOException {
      out.writeInt(delegate.size());
      for (Entry<K, V> entry : delegate.entrySet()) {
        out.writeObject(entry.getKey());

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);
      return delegate.successors(node);
    }
  }

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);
      return delegate.successors(node);
    }
  }