return EventListener.NONE;
      }
    }
  };

  ...
}
```

### 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.

    void overlapsThrowsCifsException() throws Exception {
        when(locator.overlaps(any())).thenThrow(new CIFSException("Simulated failure"));

        CIFSException ex = assertThrows(CIFSException.class, () -> locator.overlaps(other));
        assertTrue(ex.getMessage().contains("Simulated failure"));

        verify(locator).overlaps(other);
        verifyNoMoreInteractions(locator);
    }

 *    crashes the application on Android and prints a stacktrace on the JVM. (Crash reporting
 *    libraries may customize this behavior.)
 *
 * A good way to signal a failure is with a synthetic HTTP response:
 *
 * ```kotlin
 *   @Throws(IOException::class)
 *   override fun intercept(chain: Interceptor.Chain): Response {
 *     if (myConfig.isInvalid()) {
 *       return Response.Builder()

  open fun connectStart(
    route: Route,
    call: Call,
  ) {}

  /**
   * Invoked when a connection fails to be established.
   */
  open fun connectFailed(
    route: Route,
    call: Call,
    failure: IOException,
  ) {}

  /**
   * Invoked as soon as a connection is successfully established.
   */
  open fun connectEnd(
    connection: Connection,
    route: Route,
    call: Call,
  ) {}

     *
     * This method handles the primary SSO authentication flow. It checks if a user
     * is already logged in, attempts SSO authentication, and handles various
     * authentication scenarios including success, failure, and challenge responses.
     *
     * @return ActionResponse directing to the appropriate page based on authentication result
     */
    @Execute
    public ActionResponse index() {

    // incomplete.
    val creator = cache.edit("k1")!!
    creator.newSink(0).buffer().use {
      it.writeUtf8("Hello")
    }

    // Simulate a severe Filesystem failure on the first initialization.
    filesystem.setFaultyDelete(cacheDir / "k1.0.tmp", true)
    filesystem.setFaultyDelete(cacheDir, true)
    cache =

- plugin artifact retrieval problem
- plugin dependency metadata missing
- plugin dependency metadata retrieval problem
- plugin configuration problem
- plugin execution failure due to something that is known to possibly go wrong (like compilation failure)
- plugin execution error due to something that is not expected to go wrong (the compiler executable missing)

type tierMetrics struct {
	sync.RWMutex  // protects requestsCount only
	requestsCount map[string]struct {
		success int64
		failure int64
	}
	histogram *prometheus.HistogramVec
}

var globalTierMetrics = tierMetrics{
	requestsCount: make(map[string]struct {
		success int64
		failure int64
	}),
	histogram: prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Name:    "tier_ttlb_seconds",

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.lifecycle;

/**
 * Signals a failure to build because no goal was specified.
 *
 */
public class NoGoalSpecifiedException extends Exception {

    /**
     * Creates a new exception.
     *

    /**
     * No special request parameters.
     */
    NONE,

    /**
     * Wait indefinitely for a response
     */
    NO_TIMEOUT,

    /**
     * Do not retry request on failure
     */
    NO_RETRY,

    /**
     * Save the raw payload for further inspection
     */
    RETAIN_PAYLOAD