* #collectValueFromNonCancelledFuture}. As this is called after the subclass is constructed,
   * we're guaranteed to have properly initialized the subclass.
   */
  final void init() {
    /*
     * requireNonNull is safe because this is called from the constructor after `futures` is set but
     * before releaseResources could be called (because we have not yet set up any of the listeners

        current.elemCount = 0;
        // Also clear these fields so that one deleted Entry doesn't retain all elements.
        current.left = null;
        current.right = null;
        current.pred = null;
        current.succ = null;

        current = next;
      }
      successor(header, header);
      rootReference.clear();
    } else {

        current.elemCount = 0;
        // Also clear these fields so that one deleted Entry doesn't retain all elements.
        current.left = null;
        current.right = null;
        current.pred = null;
        current.succ = null;

        current = next;
      }
      successor(header, header);
      rootReference.clear();
    } else {

  }

  public void testNullWriter() throws Exception {
    // create a null writer
    Writer nullWriter = CharStreams.nullWriter();
    // write to the writer
    nullWriter.write('n');
    String test = "Test string for NullWriter";
    nullWriter.write(test);
    nullWriter.write(test, 2, 10);
    nullWriter.append(null);
    nullWriter.append(null, 0, 4);

  }

  public void testNullWriter() throws Exception {
    // create a null writer
    Writer nullWriter = CharStreams.nullWriter();
    // write to the writer
    nullWriter.write('n');
    String test = "Test string for NullWriter";
    nullWriter.write(test);
    nullWriter.write(test, 2, 10);
    nullWriter.append(null);
    nullWriter.append(null, 0, 4);

      return requireNonNull(alternatingKeysAndValues[keyOffset]).equals(key)
          ? requireNonNull(alternatingKeysAndValues[keyOffset ^ 1])
          : null;
    } else if (hashTableObject == null) {
      return null;
    }
    if (hashTableObject instanceof byte[]) {
      byte[] hashTable = (byte[]) hashTableObject;
      int mask = hashTable.length - 1;

    ImmutableBiMap<K, V> buildJdkBacked() {
      checkState(
          valueComparator == null,
          "buildJdkBacked is for tests only, doesn't support orderEntriesByValue");
      switch (size) {
        case 0:
          return of();
        case 1:
          // requireNonNull is safe because the first `size` elements have been filled in.
          Entry<K, V> onlyEntry = requireNonNull(entries[0]);

  private <T extends Iterator<E>> void internalExecuteAndCompare(
      T reference, T target, IteratorOperation method) {
    Object referenceReturnValue = null;
    PermittedMetaException referenceException = null;
    Object targetReturnValue = null;
    Exception targetException = null;

    try {
      targetReturnValue = method.execute(target);
    } catch (Exception e) { // sneaky checked exception
      targetException = e;

  private <T extends Iterator<E>> void internalExecuteAndCompare(
      T reference, T target, IteratorOperation method) {
    Object referenceReturnValue = null;
    PermittedMetaException referenceException = null;
    Object targetReturnValue = null;
    Exception targetException = null;

    try {
      targetReturnValue = method.execute(target);
    } catch (Exception e) { // sneaky checked exception
      targetException = e;

    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *
     * - a `getFooOrDefault(@CheckForNull Foo defaultValue)` method that returns