*
     * @param model The model whose report plugin configuration should be expanded, must not be <code>null</code>.
     * @param request The model building request that holds further settings, must not be {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     */

     *
     * @param request The repository request from which this cache was retrieved, must not be {@code null}.
     * @param key The key to use associate the data with, must not be {@code null}.
     * @param data The data to store in the cache, may be {@code null}.
     */
    void put(RepositoryRequest request, Object key, Object data);

    /**

     * @return The projects in the build order, never {@code null}.
     */
    List<MavenProject> getSortedProjects();

    /**
     * Gets the downstream projects of the specified project. A downstream project is a project that directly or
     * indirectly depends on the given project.
     *
     * @param project The project whose downstream projects should be retrieved, must not be {@code null}.

     *
     * @param result The interim result, may be {@code null}.
     */
    public ModelBuilderException(ModelBuilderResult result) {
        super(result.toString());
        this.result = result;
    }

    /**
     * Gets the interim result of the model building up to the point where it failed.
     *
     * @return The interim model building result or {@code null} if not available.
     */

     * value is undefined.
     *
     * @return The location of the problem, never {@code null}.
     */
    String getLocation();

    /**
     * Gets the exception that caused this problem (if any).
     *
     * @return The exception that caused this problem or {@code null} if not applicable.
     */
    Exception getException();

    /**

     * <p>
     * Examples of locations:
     * <ul>
     *   <li>Absolute file path: {@code /path/to/pom.xml}</li>
     *   <li>Relative file path: {@code ../parent/pom.xml}</li>
     *   <li>URL: {@code https://repo.maven.org/.../pom.xml}</li>
     *   <li>Description: {@code <memory>} or {@code <database>}</li>
     * </ul>
     *
     * @return a non-null string describing the source location
     */

     */
    void setRepository(ArtifactRepository remoteRepository);

    /**
     * Get the repository metadata associated with this marker.
     *
     * @return the metadata, or <code>null</code> if none loaded
     */
    Metadata getMetadata();

    /**
     * Set the metadata contents.
     *
     * @param metadata the metadata
     */
    void setMetadata(Metadata metadata);

    /**

         * Gets key-value pairs providing information about the Maven runtime.
         *
         * @return The key-value pairs, never {@code null}.
         */
        Map<String, Object> getData();
    }

    /**
     * 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.

    }

    /**
     * Creates a human-friendly string representation of the specified object.
     *
     * @param obj The object to create a string representation for, may be <code>null</code>.
     * @return The string representation, never <code>null</code>.
     */
    private String toString(Object obj) {
        String str;
        if (obj != null && obj.getClass().isArray()) {
            int n = Array.getLength(obj);

     * @return the type of the event, never {@code null}
     */
    @Nonnull
    EventType getType();

    /**
     * Gets the session from which this event originates.
     *
     * @return the current session, never {@code null}
     */
    @Nonnull
    Session getSession();

    /**
     * Gets the current project (if any).
     *
     * @return the current project or {@code empty()} if not applicable
     */