TestCloseable c3 = closer.register(TestCloseable.normal());

    assertFalse(c1.isClosed());
    assertFalse(c2.isClosed());
    assertFalse(c3.isClosed());

    closer.close();

    assertTrue(c1.isClosed());
    assertTrue(c2.isClosed());
    assertTrue(c3.isClosed());

    assertTrue(suppressor.suppressions.isEmpty());
  }

            .flatMap(x -> x);
    assertThat(concatenated).containsExactly("a", "b", "c", "d").inOrder();
    concatenated.close();
    // even without close, see doc for flatMap
    assertThat(closeCountB.get()).isEqualTo(1);
  }

  public void testConcat_refStream_closeIsPropagated_exceptionsChained() {

    }
  }

  /**
   * Calls {@link #close} if not already closed, and then resets this object back to its initial
   * state, for reuse. If data was buffered to a file, it will be deleted.
   *
   * @throws IOException if an I/O error occurred while deleting the file buffer
   */
  public synchronized void reset() throws IOException {
    try {
      close();
    } finally {
      if (memory == null) {

              return read == 0 ? -1 : read;
            }
            buf[i] = (byte) b;
          }
          return i - off;
        }

        @Override
        public void close() throws IOException {
          reader.close();
        }
      };
    }

    @Override
    public BaseEncoding omitPadding() {
      return (paddingChar == null) ? this : newInstance(alphabet, null);
    }

   * approaches 2 or 3 are used.
   */
  private static final int ZERO_COPY_CHUNK_SIZE = 512 * 1024;

  private ByteStreams() {}

  /**
   * Copies all bytes from the input stream to the output stream. Does not close or flush either
   * stream.
   *
   * <p><b>Java 9 users and later:</b> this method should be treated as deprecated; use the
   * equivalent {@link InputStream#transferTo} method instead.
   *

   * any exceptions thrown when attempting to close a closeable will be suppressed. Otherwise, the
   * <i>first</i> exception to be thrown from an attempt to close a closeable will be thrown and any
   * additional exceptions that are thrown after that will be suppressed.
   */
  @Override
  public void close() throws IOException {
    Throwable throwable = thrown;

    // close closeables in LIFO order
    while (!stack.isEmpty()) {

  //
  // 1. What about leaving/unlocking? Are you going to do
  //    guard.enter() paired with monitor.leave()? That might get
  //    confusing. It's nice for the finally block to look as close as
  //    possible to the thing right before the try. You could have
  //    guard.leave(), but that's a little odd as well because the
  //    guard doesn't have anything to do with leaving. You can't

   */
  public FluentFuture<V> finishToFuture() {
    if (compareAndUpdateState(OPEN, WILL_CLOSE)) {
      logger.get().log(FINER, "will close {0}", this);
      future.addListener(
          new Runnable() {
            @Override
            public void run() {
              checkAndUpdateState(WILL_CLOSE, CLOSING);
              close();
              checkAndUpdateState(CLOSING, CLOSED);
            }
          },

    }
  }

  // Avoid infinite recursion if a closeable's close() method throws RejectedExecutionException and
  // is closed using the direct executor.
  public void testCloseThrowsRejectedExecutionException() throws Exception {
    doThrow(new RejectedExecutionException()).when(mockCloseable).close();
    ClosingFuture<Closeable> closingFuture =
        ClosingFuture.submit(

   * Builder#build} is called, the builder is likely to perform better than an unsized {@link
   * #builder()} would have.
   *
   * <p>It is not specified if any performance benefits apply if {@code expectedSize} is close to,
   * but not exactly, the number of elements added to the builder.
   *
   * @since 23.1
   */
  public static <E> Builder<E> builderWithExpectedSize(int expectedSize) {