@Experimental
@Consumer
public interface ExtensibleEnumProvider<T extends ExtensibleEnum> extends SpiService {

    /**
     * Registers new values for the T extensible enum.
     *
     * @return a collection of T instances to register
     */
    @Nonnull
    Collection<T> provides();

     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.
     */
    void register(MavenProject project, Key key, CacheRecord record);

     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.
     */
    void register(MavenProject project, Key key, CacheRecord record);

- I could make an annotation that marked another class as its plugin discoverer, I could just add it to
  the component descriptor and when it's loaded we can add the discoverer, that would be simpler. I could
  also do this with the lister as well
i'l
// 1 the metadata -> model plugin/mojo descriptor
// 2 tools for doing the mapping
// 3 the component model -> interfaces for the plugin

// The plugin manager should load up a directory structure of plugins.

                realm.getWorld().disposeRealm(realm.getId());
            } catch (NoSuchRealmException e) {
                // ignore
            }
        }
        cache.clear();
    }

    public void register(MavenProject project, Key key, CacheRecord record) {
        // default cache does not track record usage
    }

    @Override
    public void dispose() {
        flush();
    }

        return CacheUtils.pluginHashCode(plugin);
    }

    protected static boolean pluginEquals(Plugin a, Plugin b) {
        return CacheUtils.pluginEquals(a, b);
    }

    public void register(MavenProject project, Key key, CacheRecord record) {
        // default cache does not track plugin usage
    }

    public void dispose() {
        flush();
    }

     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.
     */
    void register(MavenProject project, Key key, CacheRecord record);

                pluginArtifactsCache.put(cacheKey, e);
                pluginArtifactsCache.register(project, cacheKey, recordArtifacts);
                throw new PluginManagerException(plugin, e.getMessage(), e);
            }
        }
        pluginArtifactsCache.register(project, cacheKey, recordArtifacts);

        // create and cache extensions realms

     */
    @Nonnull
    Session withRemoteRepositories(@Nonnull List<RemoteRepository> repositories);

    /**
     * Register the given listener which will receive all events.
     *
     * @param listener the listener to register
     * @throws NullPointerException if {@code listener} is null
     */
    void registerListener(@Nonnull Listener listener);

    /**

                        projectArtifactsCache.put(cacheKey, e);
                        projectArtifactsCache.register(project, cacheKey, recordArtifacts);
                        throw e;
                    }
                }
            }
        }
        projectArtifactsCache.register(project, cacheKey, recordArtifacts);

        return recordArtifacts.getArtifacts();
    }