ExceptionHandler exceptionHandler = new DefaultExceptionHandler();
        ExceptionSummary exceptionSummary = exceptionHandler.handleException(mojoEx);

        String expectedReference = "http://cwiki.apache.org/confluence/display/MAVEN/ConnectException";
        assertEquals(expectedReference, exceptionSummary.getReference());
    }

    @Test

/**
 * Handler for exceptions thrown by event subscribers.
 *
 * @since 16.0
 */
public interface SubscriberExceptionHandler {
  /** Handles exceptions thrown by subscribers. */
  void handleException(Throwable exception, SubscriberExceptionContext context);

/**
 * Handler for exceptions thrown by event subscribers.
 *
 * @since 16.0
 */
public interface SubscriberExceptionHandler {
  /** Handles exceptions thrown by subscribers. */
  void handleException(Throwable exception, SubscriberExceptionContext context);

 */
package org.apache.maven.exception;

/**
 * Transform an exception into useful end-user message.
 *
 * @since 3.0-alpha-3
 */
public interface ExceptionHandler {
    ExceptionSummary handleException(Throwable e);

       *
       * Fortunately, exceptions rarely contain references to expensive resources.
       */

      //
      seenExceptionsLocal = newConcurrentHashSet();
      /*
       * Other handleException() callers may see this as soon as we publish it. We need to populate
       * it with the initial failure before we do, or else they may think that the initial failure
       * has never been seen before.
       */