}

  public void testWriteFromStream_doesNotCloseThatStream() throws IOException {
    TestInputStream in = new TestInputStream(new ByteArrayInputStream(new byte[10]));
    assertFalse(in.closed());
    sink.writeFrom(in);
    assertFalse(in.closed());
  }

  public void testClosesOnErrors_copyingFromByteSourceThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, READ_THROWS, CLOSE_THROWS)) {

    checkNotClosed();
    target.append(charSeq, start, end);
    return this;
  }

  private void checkNotClosed() throws IOException {
    if (closed) {
      throw new IOException("Cannot write to a closed writer.");
    }
  }

    assertEquals(Integer.MAX_VALUE, ms.headMultiset("b", CLOSED).size());
    assertEquals(Integer.MAX_VALUE, ms.headMultiset("a", CLOSED).size());

    assertEquals(3, ms.tailMultiset("c", CLOSED).size());
    assertEquals(Integer.MAX_VALUE, ms.tailMultiset("b", CLOSED).size());
    assertEquals(Integer.MAX_VALUE, ms.tailMultiset("a", CLOSED).size());
  }

  @J2ktIncompatible

    assertEquals(STRING, sink.getString());
  }

  public void testWriteFromStream_doesNotCloseThatStream() throws IOException {
    TestReader in = new TestReader();
    assertFalse(in.closed());
    sink.writeFrom(in);
    assertFalse(in.closed());
  }

  public void testWriteLines_withSpecificSeparator() throws IOException {
    sink.writeLines(ImmutableList.of("foo", "bar", "baz"), "\n");

    // from InputStream to OutputStream
    //
    /**
     * Copies from an input stream to an output stream.
     * <p>
     * Neither the input stream nor the output stream is closed.
     * </p>
     *
     * @param in the input stream (must not be {@literal null})
     * @param out the output stream (must not be {@literal null})
     * @return the number of bytes copied
     */

 * Features:
 * - Simple state management (CLOSED, OPEN, HALF_OPEN)
 * - Lock-free atomic operations
 * - Configurable thresholds and timeouts
 * - No complex dependencies
 */
public class SimpleCircuitBreaker {

    private static final Logger log = LoggerFactory.getLogger(SimpleCircuitBreaker.class);

    /**
     * Circuit breaker states
     */
    public enum State {
        CLOSED, // Normal operation

      return multiset().subMultiset(fromElement, CLOSED, toElement, OPEN).elementSet();
    }

    @Override
    public SortedSet<E> headSet(@ParametricNullness E toElement) {
      return multiset().headMultiset(toElement, OPEN).elementSet();
    }

    @Override
    public SortedSet<E> tailSet(@ParametricNullness E fromElement) {
      return multiset().tailMultiset(fromElement, CLOSED).elementSet();
    }

    @Override

    check(!closed) { "cache is closed" }
  }

  /** Force buffered operations to the filesystem. */
  @Synchronized
  @Throws(IOException::class)
  override fun flush() {
    if (!initialized) return

    checkNotClosed()
    trimToSize()
    journalWriter!!.flush()
  }

  @Synchronized fun isClosed(): Boolean = closed

      readControlFrame()
    } else {
      readMessageFrame()
    }
  }

  @Throws(IOException::class, ProtocolException::class)
  private fun readHeader() {
    if (closed) throw IOException("closed")

    // Disable the timeout to read the first byte of a new frame.
    val b0: Int
    val timeoutBefore = source.timeout().timeoutNanos()
    source.timeout().clearTimeout()
    try {

        assertFalse(auth.isClosed());

        // Close the authenticator
        auth.close();

        // Verify it's closed
        assertTrue(auth.isClosed());
        // Cannot check password after closing as it now throws IllegalStateException
        // This is actually good security practice - closed authenticators cannot be accessed

        // Verify multiple closes don't cause issues