if (pluginBindings != null) {
            final int len = pluginBindings.length;

            if (len < 2 || len % 2 != 0) {
                throw new IllegalArgumentException("Plugin bindings must have more than 0, even count of elements");
            }

            defaultBindings = new LinkedHashMap<>(len / 2);

            for (int i = 0; i < len; i += 2) {

  <version>0.1</version>
  <packaging>pom</packaging>

  <name>Maven Integration Test :: MNG-3943</name>
  <description>
    Test that plugin executions are properly merged during inheritance, even if the child uses a different
    plugin version than the parent.
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>

    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3916</name>
  <description>
    Test that plugin executions are properly merged during inheritance, even if the child plugin section has no
    version.
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>
        <artifactId>maven-it-plugin-a</artifactId>

        }

        ArtifactTransferEvent event = wrap(transferEvent);
        event.setDataBuffer(buffer);
        event.setDataOffset(0);
        event.setDataLength(length);
        event.setTransferredBytes(transferred);

        listener.transferProgress(event);
    }

    public void transferStarted(TransferEvent transferEvent) {

        scope.beforeMojoExecution(event);
        scope.afterMojoExecutionSuccess(event);
        scope.afterExecutionFailure(event);

        assertEquals(1, beforeExecution.get());
        assertEquals(1, afterExecutionSuccess.get());
        assertEquals(1, afterExecutionFailure.get());

        scope.exit();
    }

    }

    public void beforeMojoExecution(MojoExecutionEvent event) throws MojoExecutionException {
        for (WeakMojoExecutionListener provided : getProvidedListeners()) {
            provided.beforeMojoExecution(event);
        }
    }

    public void afterMojoExecutionSuccess(MojoExecutionEvent event) throws MojoExecutionException {

    }

    /**
     * Initializes the spy.
     *
     * @param context The event spy context, never {@code null}.
     */
    void init(Context context) throws Exception;

    /**
     * Notifies the spy of some build event/operation.
     *
     * @param event The event, never {@code null}.
     * @see org.apache.maven.settings.building.SettingsBuildingRequest

        if (listener != null) {
            RepositoryEvent.Builder event = new RepositoryEvent.Builder(session, EventType.METADATA_INVALID);
            event.setTrace(trace);
            event.setMetadata(metadata);
            event.setException(exception);
            event.setRepository(repository);
            listener.metadataInvalid(event.build());
        }
    }

 * @since 3.1.2
 */
public interface MojoExecutionListener {
    void beforeMojoExecution(MojoExecutionEvent event) throws MojoExecutionException;

    void afterMojoExecutionSuccess(MojoExecutionEvent event) throws MojoExecutionException;

    void afterExecutionFailure(MojoExecutionEvent event);

 *
 * @since 4.0.0
 */
@Experimental
@FunctionalInterface
@Consumer
public interface Listener {
    void onEvent(@Nonnull Event event);