WebApiUtil.setError(503, "Service Unavailable");
        } catch (Exception e) {
            fail("setError should handle various status codes gracefully: " + e.getMessage());
        }
    }

    @Test
    public void test_validate_noRequest() {
        // Test validate when no HTTP request is available
        try {
            WebApiUtil.validate();

   * @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
   *     greater than {@code b}; or zero if they are equal
   */
  @SuppressWarnings("InlineMeInliner") // Integer.compare unavailable under GWT+J2CL
  public static int compare(long a, long b) {
    return Longs.compare(flip(a), flip(b));
  }

  /**
   * Returns the least value present in {@code array}, treating values as unsigned.
   *

   * @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
   *     greater than {@code b}; or zero if they are equal
   */
  @SuppressWarnings("InlineMeInliner") // Integer.compare unavailable under GWT+J2CL
  public static int compare(int a, int b) {
    return Ints.compare(flip(a), flip(b));
  }

  /**
   * Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
   *

        }
    }

    /**
     * Handle node unavailable events
     */
    private void handleNodeUnavailable(WitnessNotification notification) {
        log.warn("Node unavailable: {}", notification.getResourceName());
        // Could trigger failover logic here
    }

    /**
     * Handle node available events
     */

REGISTER_OP("TestNonCommUnavailable")
    .Output("out: string")
    .Doc(R"doc(Test non-communication op throwing Unavailable error.)doc");

REGISTER_OP("TestCommUnavailable")
    .Output("out: string")
    .SetIsDistributedCommunication()
    .Doc(R"doc(Test communication op throwing Unavailable error.)doc");

// Kernel that throws an Unavailable error.
class TestUnavailableErrorOp : public tensorflow::OpKernel {
 public:

         * reflectively before attempting to access UnsafeComparator. Or, better yet, allow
         * UnsafeComparator to still initialize correctly even if Unsafe is unavailable. This would
         * protect against users that automatically preinitialize internal classes that they've seen
         * initialized in their apps in the past. To do that, we may need to move the references to

   * The "getStackTraceElementMethod" method, only available on some JDKs so we use reflection to
   * find it when available. When this is null, use the slow way.
   */
  @J2ktIncompatible @GwtIncompatible // java.lang.reflect
  private static final @Nullable Method getStackTraceElementMethod =
      (jla == null) ? null : getGetMethod();

  /**
   * The "getStackTraceDepth" method, only available on some JDKs so we use reflection to find it

                auth_error: 'AI service authentication failed. Please contact the administrator.',
                service_unavailable: 'The AI service is temporarily unavailable. Please try again later.',
                timeout: 'The request timed out. Please try again.',
                context_length_exceeded: 'The message is too long to process. Please shorten it and try again.',

   */
  open fun callStart(call: Call) {
  }

  /**
   * Invoked for calls that were not executed immediately because resources weren't available. The
   * call will remain in the queue until resources are available.
   *
   * Use [Dispatcher.maxRequests] and [Dispatcher.maxRequestsPerHost] to configure how many calls
   * OkHttp performs concurrently.
   */
  open fun dispatcherQueueStart(

    * This ensures that attachment and detachment of volumes is independent of any single nodes’ availability. Meaning, if a node or kubelet becomes unavailable for any reason, the volumes attached to that node will be detached so they are free to be attached to other nodes.