default:
        Object[] keys = new Object[size];
        Object[] values = new Object[size];
        if (sameComparator) {
          // Need to check for nulls, but don't need to sort or validate.
          for (int i = 0; i < size; i++) {
            // requireNonNull is safe because the first `size` elements have been filled in.

    }
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(final Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {

 *       scalability or other performance factors (see the separate "jtreg" tests for a set intended
 *       to check these for the most central aspects of functionality.) So, most tests use the
 *       smallest sensible numbers of threads, collection sizes, etc needed to check basic
 *       conformance.
 *   <li>The test classes currently do not declare inclusion in any particular package to simplify

  @Override
  protected void setUp() throws Exception {
    // Load the "normal" copy of SettableFuture and related classes.
    SettableFuture<?> unused = SettableFuture.create();
    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation
    // cause system property.  This allows us to run with both settings of the property in one jvm

  @Override
  public void clear() {
    if (needsAllocArrays()) {
      return;
    }
    this.firstEntry = ENDPOINT;
    this.lastEntry = ENDPOINT;
    // Either both arrays are null or neither is, but we check both to satisfy the nullness checker.
    if (predecessor != null && successor != null) {
      Arrays.fill(predecessor, 0, size(), 0);
      Arrays.fill(successor, 0, size(), 0);
    }
    super.clear();
  }

     * bad. We do the leadingZeros check to avoid the division below if at all possible.
     *
     * Otherwise, if b == Long.MIN_VALUE, then the only allowed values of a are 0 and 1. We take
     * care of all a < 0 with their own check, because in particular, the case a == -1 will
     * incorrectly pass the division check below.
     *
     * In all other cases, we check that either a is 0 or the result is consistent with division.

    /*
     * Safe because all we do is remove values for the key, not add them. (If we wanted to make sure
     * to call getCopy and removeAllNodes only with a true K, then we could check containsKey first.
     * But that check wouldn't eliminate the warnings.)
     */
    @SuppressWarnings({"unchecked", "nullness"})
    K castKey = (K) key;
    List<V> oldValues = getCopy(castKey);
    removeAllNodes(castKey);

    try {
      Hashing.hmacMd5(badKey);
      fail();
    } catch (IllegalArgumentException expected) {
    } catch (NullPointerException toleratedOnAndroid) {
      // TODO(cpovirk): In an ideal world, we'd check here that we're running on Android.
    }
  }

  public void testEmptyInputs() throws Exception {
    String knownOutput = "8cbf764cbe2e4623d99a41354adfd390";

    Mac mac = Mac.getInstance("HmacMD5");

   *
   * <p>The array must be internally created.
   */
  static <E> ImmutableList<E> asImmutableList(Object[] elements) {
    return asImmutableList(elements, elements.length);
  }

  /**
   * Views the array as an immutable list. Copies if the specified range does not cover the complete
   * array. Does not check for nulls.
   */

   * direction," converting empty strings to {@code null}, you can use {@link #emptyToNull}.
   *
   * @param string a string reference to check
   * @return {@code true} if the string is null or is the empty string
   */
  public static boolean isNullOrEmpty(@CheckForNull String string) {
    return Platform.stringIsNullOrEmpty(string);
  }

  /**