checkNotNull(sink);

    Closer closer = Closer.create();
    try {
      Reader reader = closer.register(openStream());
      Writer writer = closer.register(sink.openStream());
      return CharStreams.copy(reader, writer);
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**

    Closer closer = new Closer(suppressor);

    TestCloseable c1 = closer.register(TestCloseable.normal());
    TestCloseable c2 = closer.register(TestCloseable.normal());

    IOException exception = new IOException();

    try {
      try {
        throw exception;
      } catch (Throwable e) {
        throw closer.rethrow(e);
      } finally {
        closer.close();
      }

 *
 * {@snippet :
 * FluentFuture<UserName> userName =
 *     ClosingFuture.submit(
 *             closer -> closer.eventuallyClose(database.newTransaction(), closingExecutor),
 *             executor)
 *         .transformAsync((closer, transaction) -> transaction.queryClosingFuture("..."), executor)
 *         .transform((closer, result) -> result.get("userName"), directExecutor())

    Closer closer = new Closer(suppressor);

    TestCloseable c1 = closer.register(TestCloseable.normal());
    TestCloseable c2 = closer.register(TestCloseable.normal());

    IOException exception = new IOException();

    try {
      try {
        throw exception;
      } catch (Throwable e) {
        throw closer.rethrow(e);
      } finally {
        closer.close();
      }

  // 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(

  // 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(

                  return true;
                }
                return false;
              }
            },
            isParallel)
        .onClose(streamA::close)
        .onClose(streamB::close);
  }

  /**
   * Invokes {@code consumer} once for each pair of <i>corresponding</i> elements in {@code streamA}

            this.classLoader = classLoader;
        }

        void close() {
            try {
                classLoader.clearCache();
                classLoader.close();
            } catch (final IOException e) {
                LogManager.getLogger(GroovyEngine.class).warn("Failed to close GroovyClassLoader", e);
            }
        }
    }

   * message buffer (16 MiB) will be rejected and trigger a [graceful shutdown][close] of this web
   * socket. This method returns false in that case, and in any other case where this web socket is
   * closing, closed, or canceled.
   *
   * This method returns immediately.
   */
  fun send(text: String): Boolean

  /**

                  return true;
                }
                return false;
              }
            },
            isParallel)
        .onClose(streamA::close)
        .onClose(streamB::close);
  }

  /**
   * Invokes {@code consumer} once for each pair of <i>corresponding</i> elements in {@code streamA}