// Test with an unrecognized field in the ticket
        // Note: In the actual implementation, field 99 would come after mandatory fields,
        // so decryption happens first. We test with a mocked successful decryption.
        byte[] token = createTestTicketBytes(new BigInteger(KerberosConstants.KERBEROS_VERSION), SERVER_REALM, SERVER_PRINCIPAL_NAME,

  // operation in the constructor.
  //
  // 1. In the listener that performs the callback. In this case it is fine since inputFuture is
  //    assigned prior to calling addListener, and addListener happens-before any invocation of the
  //    listener. Notably, this means that 'volatile' is unnecessary to make 'inputFuture' visible
  //    to the listener.
  //

    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens
    // in our test environment, which foils the purpose of this test, so we disable the logic for
    // our test by setting a static field. We are changing the field in the parallel version of FRQ

   * are running concurrently.
   *
   * <p>{@linkplain Executor#execute executed} tasks have a happens-before order as defined in the
   * Java Language Specification. Tasks execute with the same happens-before order that the function
   * calls to {@link Executor#execute execute()} that submitted those tasks had.
   *

      cp >>>= 4;
      dest[4] = upperHexDigits[0x8 | (cp & 0x3)];
      cp >>>= 2;
      dest[2] = upperHexDigits[cp & 0x7];
      return dest;
    } else {
      // If this ever happens it is due to bug in UnicodeEscaper, not bad input.
      throw new IllegalArgumentException("Invalid unicode character value " + cp);
    }
  }

    return response;
  }
}
```

A call to `chain.proceed(request)` is a critical part of each interceptor’s implementation. This simple-looking method is where all the HTTP work happens, producing a response to satisfy the request. If `chain.proceed(request)` is being called more than once previous response bodies must be closed.

### Events with Failures

When an operation fails, a failure method is called. This is `connectFailed()` for failures while building a connection to the server, and `callFailed()` when the HTTP call fails permanently. When a failure happens it is possible that a `start` event won’t have a corresponding `end` event.

![Events Diagram](../assets/images/******@****.***)

### Events with Retries and Follow-Ups

    listenableFuture.addListener(singleCallListener, directExecutor());
    /*
     * Don't shut down until the listenInPoolThread task has been accepted to
     * run. We want to see what happens when it's interrupted, not when it's
     * rejected.
     */
    submitSuccessful.await();
    executorService.shutdownNow();
    abstractFuture.set(DATA1);
    assertThat(listenableFuture.get()).isEqualTo(DATA1);

   * WritableByteChannel)}:
   *
   * <ol>
   *   <li>Use sendfile(2) or equivalent. Requires that both the input channel and the output
   *       channel have their own file descriptors. Generally this only happens when both channels
   *       are files or sockets. This performs zero copies - the bytes never enter userspace.
   *   <li>Use mmap(2) or equivalent. Requires that either the input channel or the output channel

      if (e.getCause() instanceof IllegalArgumentException) {
        /*
         * IllegalArgumentException is the one unchecked exception that we know is likely to happen
         * (thanks to the checkArgument calls in getAnnotatedMethodsNotCached). If it happens, we'd
         * prefer to propagate an IllegalArgumentException to the caller. However, we don't want to