public void metadataInvalid(RepositoryEvent event) {
        Exception exception = event.getException();

        Object metadata;
        if (event.getMetadata().getFile() != null) {
            metadata = event.getMetadata().getFile();
        } else {
            metadata = event.getMetadata();
        }

        String errorType = " is invalid";
        if (exception instanceof FileNotFoundException) {

        println("metadataDeployed", event.getMetadata() + " to " + event.getRepository());
    }

    public void metadataDeploying(RepositoryEvent event) {
        println("metadataDeploying", event.getMetadata() + " to " + event.getRepository());
    }

    public void metadataInstalled(RepositoryEvent event) {
        println("metadataInstalled", event.getMetadata() + " to " + event.getFile());
    }

    private final Date timestamp;

    VersionsMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
        this(session, request.getMetadata());
    }

    VersionsMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
        this(session, request.getMetadata());
    }

    private VersionsMetadataGenerator(RepositorySystemSession session, Collection<? extends Metadata> metadatas) {

        addPluginMapping(goalPrefix, artifactId, artifactId);
    }

    public void addPluginMapping(String goalPrefix, String artifactId, String name) {
        List<Plugin> plugins = getMetadata().getPlugins();
        boolean found = false;
        for (Iterator<Plugin> i = plugins.iterator(); i.hasNext() && !found; ) {
            Plugin plugin = i.next();
            if (plugin.getPrefix().equals(goalPrefix)) {

    private final Date timestamp;

    PluginsMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
        this(session, request.getMetadata());
    }

    PluginsMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
        this(session, request.getMetadata());
    }

    private PluginsMetadataGenerator(RepositorySystemSession session, Collection<? extends Metadata> metadatas) {

                    if (!remoteFile.exists()) {
                        download.setException(new MetadataNotFoundException(download.getMetadata(), repository));
                    } else {
                        download.setException(new MetadataTransferException(download.getMetadata(), repository, e));
                    }
                }
            }
        }
    }

    private String path(Artifact artifact) {

    private final Date timestamp;

    PluginsMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
        this(session, request.getMetadata());
    }

    PluginsMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
        this(session, request.getMetadata());
    }

    private PluginsMetadataGenerator(RepositorySystemSession session, Collection<? extends Metadata> metadatas) {

        this.metadata.merge(repoMetadata.getMetadata());
    }

    public void merge(ArtifactMetadata metadata) {
        // TODO not sure that it should assume this, maybe the calls to addMetadata should pre-merge, then artifact
        // replaces?
        AbstractRepositoryMetadata repoMetadata = (AbstractRepositoryMetadata) metadata;
        this.metadata.merge(repoMetadata.getMetadata());
    }

    private final Date timestamp;

    VersionsMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
        this(session, request.getMetadata());
    }

    VersionsMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
        this(session, request.getMetadata());
    }

    private VersionsMetadataGenerator(RepositorySystemSession session, Collection<? extends Metadata> metadatas) {

            if (repoMetadata.isSnapshot() && (previousMetadata != null)) {
                previousMetadata.put(remoteRepository, metadata);
            }

            if (repoMetadata.getMetadata() != null) {
                setRepository = repoMetadata.getMetadata().merge(metadata);
            } else {
                repoMetadata.setMetadata(metadata);
                setRepository = true;
            }
        }