* <p>
 * A note to the reader;
 * </p>
 * <p>
 * There are several issues/discussions regarding how "aggregator" plugins should be handled.
 * Read for instance http://docs.codehaus.org/display/MAVEN/Deterministic+Lifecycle+Planning
 * </p>
 * <p>
 * In their current implementation they are "bolted" onto the lifecycle by separating them

    @Nullable
    String getModelId();

    @Nullable
    String getLocation();

    boolean isAddDefaultEntities();

    interface Transformer {
        /**
         * Interpolate the value read from the xml document
         *
         * @param source    The source value
         * @param fieldName A description of the field being interpolated. The implementation may use this to
         *                  log stuff.

            return properties;
        }

        try (Reader reader = Files.newBufferedReader(path)) {
            properties.load(reader);
        } catch (IOException e) {
            LOGGER.warn("Unable to read {}. The --resume / -r feature will not work.", path);
        }

        return properties;
    }

    // This method is made package-private for testing purposes

     * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
     * which the settings were read.
     *
     * @return The hint about the source of the problem or an empty string if unknown, never {@code null}.
     */
    String getSource();

    /**

        moduleInfo = new HashMap<>();
        pathTypes = new HashMap<>();
    }

    /**
     * Gets module information for the given JAR file or output directory.
     * Module descriptors are read when first requested, then cached.
     */
    PathModularization getModuleInfo(Path path) throws IOException {
        PathModularization info = moduleInfo.get(path);
        if (info == null) {

     *
     * @return The assembled model, never {@code null}.
     */
    @Nonnull
    Model getEffectiveModel();

    /**
     * Gets the specified raw model as it was read from a model source. Apart from basic validation, a raw model has not
     * undergone any updates by the model builder, e.g. reflects neither inheritance nor interpolation. The model

            throws IOException;

    /**
     * Calculates checksums for specified stream. Upon this method returns, the stream will be depleted (fully read)
     * but not closed.
     *
     * @param stream      The stream for which to calculate checksums, must not be {@code null}.
     * @param algorithms  The checksum algorithms to use, must not be {@code null}.

        moduleInfo = new HashMap<>();
        pathTypes = new HashMap<>();
    }

    /**
     * Gets module information for the given JAR file or output directory.
     * Module descriptors are read when first requested, then cached.
     */
    PathModularization getModuleInfo(Path path) throws IOException {
        PathModularization info = moduleInfo.get(path);
        if (info == null) {

            }
        } else if (metadataFile.exists()) {
            try (InputStream input = Files.newInputStream(metadataFile.toPath())) {
                metadata = new Metadata(new MetadataStaxReader().read(input, false));
            }
        }

        boolean changed;

        // If file could not be found or was not valid, start from scratch
        if (metadata == null) {
            metadata = this.metadata;

        try (InputStream inputStream = Files.newInputStream(file)) {
            org.apache.maven.model.Model model =
                    new org.apache.maven.model.Model(new MavenStaxReader().read(inputStream));
            project = new MavenProject(model);
            project.setRootDirectory(Paths.get("src/test/resources/consumer/trivial"));
            project.setOriginalModel(model);