import static java.util.Objects.requireNonNull;

/**
 * A class building reverse tree using {@link CollectStepData} trace data provided in {@link RepositoryEvent}
 * events fired during collection.
 *
 * @since 3.9.0
 */
class ReverseTreeRepositoryListener extends AbstractRepositoryListener {
    @Override
    public void artifactResolved(RepositoryEvent event) {

/**
 * Holds data relevant for a model building event.
 *
 */
public interface ModelBuildingEvent {

    /**
     * Gets the model being built. The precise state of this model depends on the event being fired.
     *
     * @return The model being built, never {@code null}.
     */
    Model model();

    Consumer<Model> update();

    /**
     * Gets the model building request being processed.
     *

become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

Second, the timer channel associated with a `Timer` or `Ticker` is
now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees

			}

			// Set tcp user timeout in addition to the keep-alive - tcp-keepalive is not enough to close a socket
			// with dead end because tcp-keepalive is not fired when there is data in the socket buffer.
			//    https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/
			// This is a sensitive configuration, it is better to set it to high values, > 60 secs since it can

0.001 requestHeadersEnd
0.002 responseHeadersStart
0.082 responseHeadersEnd
0.082 responseBodyStart
0.082 responseBodyEnd
0.083 connectionReleased
0.083 callEnd
```

Notice how no connect events are fired for the second call. It reused the connection from the first request for dramatically better performance.

### EventListener.Factory

    ImmutableList<Service> copy = ImmutableList.copyOf(services);
    if (copy.isEmpty()) {
      // Having no services causes the manager to behave strangely. Notably, listeners are never
      // fired. To avoid this we substitute a placeholder service.
      logger
          .get()
          .log(
              Level.WARNING,
              "ServiceManager configured with no services.  Is your application configured"

                if (parent == null) {
                    //
                    // At this point the DefaultModelBuildingListener has fired and it populates the
                    // remote repositories with those found in the pom.xml, along with the existing externally
                    // defined repositories.
                    //

 *  New: We've added `requestFailed()` and `responseFailed()` methods to `EventListener`. These
    are called instead of `requestBodyEnd()` and `responseBodyEnd()` in some failure situations.
    They may also be fired in cases where no event was published previously. In this release we did
    an internal rewrite of our event code to fix problems where events were lost or unbalanced.

           : 'modal-static'\n}\n\nconst Selector = {\n  DIALOG         : '.modal-dialog',\n  MODAL_BODY     : '.modal-body',\n  DATA_TOGGLE    : '[data-toggle=\"modal\"]',\n  DATA_DISMISS   : '[data-dismiss=\"modal\"]',\n  FIXED_CONTENT  : '.fixed-top, .fixed-bottom, .is-fixed, .sticky-top',\n  STICKY_CONTENT : '.sticky-top'\n}\n\n/**\n * ------------------------------------------------------------------------\n * Class Definition\n * ------------------------------------------------------------------------\n...

SHOW               : 'show'\n}\n\nconst Selector = {\n  DIALOG         : '.modal-dialog',\n  MODAL_BODY     : '.modal-body',\n  DATA_TOGGLE    : '[data-toggle=\"modal\"]',\n  DATA_DISMISS   : '[data-dismiss=\"modal\"]',\n  FIXED_CONTENT  : '.fixed-top, .fixed-bottom, .is-fixed, .sticky-top',\n  STICKY_CONTENT : '.sticky-top'\n}\n\n/**\n * ------------------------------------------------------------------------\n * Class Definition\n * ------------------------------------------------------------------------\n...