* 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

    // 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
     */

            It will be closed in 14 days if no further activity occurs.
            If you don't want the stale bot to close it, then set a milestone for it.
          days-before-pr-close: 14
          close-pr-message: >

   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)
    val source: Source =
      object : Source {
        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(

    withLock {
      cancel = !source.finished && source.closed && (sink.finished || sink.closed)
      open = isOpen
    }
    if (cancel) {
      // RST this stream to prevent additional data from being sent. This is safe because the input
      // stream is closed (we won't use any further bytes) and the output stream is either finished
      // or closed (so RSTing both streams doesn't cause harm).

   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)
    val source: Source =
      object : Source {
        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(

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

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

 *
 *  * **Closing:** one of the peers on the web socket has initiated a graceful shutdown. The web
 *    socket will continue to transmit already-enqueued messages but will refuse to enqueue new
 *    ones.
 *
 *  * **Closed:** the web socket has transmitted all of its messages and has received all messages
 *    from the peer.
 *
 * Web sockets may fail due to HTTP upgrade problems, connectivity problems, or if either peer

                log.info("[{}] Circuit breaker closing after {} successful attempts", name, successes);
                transitionTo(State.CLOSED);
            }
        } else if (currentState == State.CLOSED) {
            // Reset failure count on success in closed state
            failureCount.set(0);
        }

        // Notify listeners
        for (CircuitBreakerListener listener : listeners) {

    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");