* property {@code maven.ext.class.path} on the command line. As soon as dependency injection is set up, Maven
 * looks up all implementers of this interface and calls their {@link #init(Context)} method. Note:
 * Implementors are strongly advised to inherit from {@link AbstractEventSpy} instead of directly implementing this
 * interface.
 * @since 3.0.2
 */
public interface EventSpy {
    /**

 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again
 *   <li>throwing an exception of some kind

 * under the License.
 */
package org.apache.maven.eventspy;

/**
 * A skeleton eventspy that does nothing other than helping implementors.
 * @since 3.0.2
 */
public abstract class AbstractEventSpy implements EventSpy {

    public void init(Context context) throws Exception {}

    public void onEvent(Object event) throws Exception {}

    public void close() throws Exception {}

 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">Notes
 *       for implementors</a>
 * </ul>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 * @since 20.0
 */
@Beta

 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">Notes
 *       for implementors</a>
 * </ul>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta

 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">Notes
 *       for implementors</a>
 * </ul>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @since 20.0
 */
@Beta

 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">Notes
 *       for implementors</a>
 * </ul>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @since 20.0
 */
@Beta

     */
    void addRepository(org.apache.maven.model.Repository repository, boolean replace) throws InvalidRepositoryException;

    /**
     * Clones this resolver for usage in a forked resolution process. In general, implementors need not provide a deep
     * clone. The only requirement is that invocations of {@link #addRepository(Repository)} on the clone do not affect
     * the state of the original resolver and vice versa.
     *

 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#synchronization">
 *       Synchronization policy</a>
 *   <li><a href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">Notes
 *       for implementors</a>
 * </ul>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta

   * factor, and concurrency settings.
   */
  public static <E> ConcurrentHashMultiset<E> create() {
    // TODO(schmoe): provide a way to use this class with other (possibly arbitrary)
    // ConcurrentMap implementors. One possibility is to extract most of this class into
    // an AbstractConcurrentMapMultiset.
    return new ConcurrentHashMultiset<>(new ConcurrentHashMap<E, AtomicInteger>());
  }

  /**