* @return the last element of {@code iterator}
   * @since 3.0
   */
  @ParametricNullness
  public static <T extends @Nullable Object> T getLast(
      Iterator<? extends T> iterator, @ParametricNullness T defaultValue) {
    return iterator.hasNext() ? getLast(iterator) : defaultValue;
  }

  /**
   * Calls {@code next()} on {@code iterator}, either {@code numberToAdvance} times or until {@code

   * @return the last element of {@code iterator}
   * @since 3.0
   */
  @ParametricNullness
  public static <T extends @Nullable Object> T getLast(
      Iterator<? extends T> iterator, @ParametricNullness T defaultValue) {
    return iterator.hasNext() ? getLast(iterator) : defaultValue;
  }

  /**
   * Calls {@code next()} on {@code iterator}, either {@code numberToAdvance} times or until {@code

        assertEquals(AvPair.MsvAvFlags, pair.getType(), "Pair type should be MsvAvFlags");
        assertTrue(pair instanceof AvFlags, "Should be decoded as AvFlags");
        assertEquals(0x12345678, ((AvFlags) pair).getFlags(), "Flags value should match");
    }

    /**
     * Test decode with multiple AvPairs
     */
    @Test
    @DisplayName("Decode multiple AvPairs with EOL")

    private final int size;

    ComplementRanges(ImmutableList<Range<C>> ranges) {
      this.ranges = ranges;
      this.positiveBoundedBelow = ranges.get(0).hasLowerBound();
      this.positiveBoundedAbove = Iterables.getLast(ranges).hasUpperBound();

      int size = ranges.size() - 1;
      if (positiveBoundedBelow) {
        size++;
      }
      if (positiveBoundedAbove) {
        size++;
      }

     * @return the last element, or null if the collection is empty
     * @since Java 21
     */
    public static <E> E getLast(final SequencedCollection<E> collection) {
        return collection.isEmpty() ? null : collection.getLast();
    }

    /**
     * Adds an element to the beginning of a sequenced collection.
     *
     * @param <E> the element type

    private final int size;

    ComplementRanges(ImmutableList<Range<C>> ranges) {
      this.ranges = ranges;
      this.positiveBoundedBelow = ranges.get(0).hasLowerBound();
      this.positiveBoundedAbove = Iterables.getLast(ranges).hasUpperBound();

      int size = ranges.size() - 1;
      if (positiveBoundedBelow) {
        size++;
      }
      if (positiveBoundedAbove) {
        size++;
      }

    @Override
    public void setUid(final int uid) {
        // ignore
    }

    /**
     * Gets the flags for this message.
     *
     * @return the flags
     */
    public final int getFlags() {
        return this.flags;
    }

    /**
     * Adds the specified flags to this message.
     *
     * @param flag the flags to add
     */
    public final void addFlags(final int flag) {

    @Override
    public E getFirst() {
      synchronized (mutex) {
        return delegate().getFirst();
      }
    }

    @Override
    public E getLast() {
      synchronized (mutex) {
        return delegate().getLast();
      }
    }

    @Override
    public @Nullable E peekFirst() {
      synchronized (mutex) {
        return delegate().peekFirst();
      }
    }

    @Override
    public E getFirst() {
      synchronized (mutex) {
        return delegate().getFirst();
      }
    }

    @Override
    public E getLast() {
      synchronized (mutex) {
        return delegate().getLast();
      }
    }

    @Override
    public @Nullable E peekFirst() {
      synchronized (mutex) {
        return delegate().peekFirst();
      }
    }

      return server;
    }

    public Inet4Address getClient() {
      return client;
    }

    public int getPort() {
      return port;
    }

    public int getFlags() {
      return flags;
    }
  }

  /**
   * Evaluates whether the argument is a Teredo address.
   *
   * <p>Teredo addresses begin with the {@code "2001::/32"} prefix.
   *