List<String> alreadyThere = newArrayList("already", "there");
    List<String> freshlyAdded = newArrayList("freshly", "added");

    boolean changed = Iterables.addAll(alreadyThere, freshlyAdded);
    assertThat(alreadyThere).containsExactly("already", "there", "freshly", "added").inOrder();
    assertTrue(changed);
  }

  private static void assertCanIterateAgain(Iterable<?> iterable) {

    }

    /**
     * The number of permutations with repeated elements is calculated as follows:
     *
     * <ul>
     *   <li>For an empty list, it is 1 (base case).
     *   <li>When r numbers are added to a list of n-r elements, the number of permutations is
     *       increased by a factor of (n choose r).
     * </ul>
     */
    private static <E> int calculateSize(

  // Historically Invokable inherited from java.lang.reflect.AccessibleObject. That's no longer the
  // case, but we do check that its API still has the same public methods. We exclude some methods
  // that were added in Java 9 and that people probably weren't calling via Invokable, namely
  // `boolean canAccess(Object)` and `boolean trySetAccessible()`.
  public void testApiCompatibleWithAccessibleObject() {

   * other utilities in this package.
   *
   * <p><b>Note:</b> this method simply delegates to the JDK method {@link Float#compare}. It is
   * provided for consistency with the other primitive types, whose compare methods were not added
   * to the JDK until JDK 7.
   *
   * @param a the first {@code float} to compare
   * @param b the second {@code float} to compare
   * @return the result of invoking {@link Float#compare(float, float)}
   */

 * creation methods appear to adhere doggedly to the original intent of the "mapped" address: all
 * "mapped" addresses return {@link Inet4Address} objects.
 *
 * <p>For added safety, it is common for IPv6 network operators to filter all packets where either
 * the source or destination address appears to be a "compat" or "mapped" address. Filtering

  }

  // ConcurrentMap methods

  @Override
  public boolean isEmpty() {
    /*
     * Sum per-segment modCounts to avoid mis-reporting when elements are concurrently added and
     * removed in one segment while checking another, in which case the table was never actually
     * empty at any point. (The sum ensures accuracy up through at least 1<<31 per-segment

    return new HashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code HashSet} instance initially containing the given elements.
   *
   * <p><b>Note:</b> if elements are non-null and won't be added or removed after this point, use
   * {@link ImmutableSet#of()} or {@link ImmutableSet#copyOf(Object[])} instead. If {@code E} is an
   * {@link Enum} type, use {@link EnumSet#of(Enum, Enum[])} instead. Otherwise, strongly consider

    int added = 0;
    boolean interrupted = false;
    try {
      while (added < numElements) {
        // we could rely solely on #poll, but #drainTo might be more efficient when there are
        // multiple elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
        added += q.drainTo(buffer, numElements - added);

        [many forms](https://github.com/google/guava/wiki/PhilosophyExplained#utility), but taking
        the time to discuss them in detail will make it much clearer why this feature should be
        added to Guava.


        Please fill out the following fields to give us a better understanding of your proposed
        feature and its potential value for other Guava users.

  - type: textarea
    attributes:

   * </ul>
   *
   * <p>Note that {@code StandardSystemProperty} does not provide constants for more recently added
   * properties, including:
   *
   * <ul>
   *   <li>{@code java.vendor.version} (added in Java 11, listed as optional as of Java 13)
   *   <li>{@code jdk.module.*} (added in Java 9, optional)
   * </ul>
   */
  @CheckForNull
  public String value() {
    return System.getProperty(key);