checkScopeUpdate(Artifact.SCOPE_RUNTIME, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM);
        checkScopeUpdate(Artifact.SCOPE_RUNTIME, Artifact.SCOPE_TEST, Artifact.SCOPE_RUNTIME);

        /* farthest = system */
        checkScopeUpdate(Artifact.SCOPE_SYSTEM, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE);
        checkScopeUpdate(Artifact.SCOPE_SYSTEM, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_PROVIDED);

                scopes = Arrays.asList(
                        Artifact.SCOPE_COMPILE, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_RUNTIME);
            } else if (Artifact.SCOPE_RUNTIME_PLUS_SYSTEM.equals(classpath)) {
                scopes = Arrays.asList(Artifact.SCOPE_COMPILE, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_RUNTIME);
            } else if (Artifact.SCOPE_TEST.equals(classpath)) {

    }

    @Provides
    static Session newSession(RepositorySystem system, Lookup lookup) {
        Map<String, String> properties = new HashMap<>();
        // Env variables prefixed with "env."
        System.getenv().forEach((k, v) -> properties.put("env." + k, v));
        // Java System properties
        System.getProperties().forEach((k, v) -> properties.put(k.toString(), v.toString()));

    @Nonnull
    Map<String, String> getUserProperties();

    /**
     * Returns immutable system properties to use for interpolation. The system properties are collected from the
     * runtime environment such as {@link System#getProperties()} and environment variables
     * (prefixed with {@code env.}).
     *
     * @return the system properties, never {@code null}
     */
    @Nonnull
    Map<String, String> getSystemProperties();

                new File(System.getProperty("basedir", "."), "target/local-repo").getAbsoluteFile());
    }

    public ArtifactRepository createDefaultRemoteRepository() throws InvalidRepositoryException {
        return new MavenArtifactRepository(
                DEFAULT_REMOTE_REPO_ID,
                "file://"
                        + new File(System.getProperty("basedir", "."), "src/test/remote-repo")

        MojoExecution exec = newMojoExecution();

        MavenSession session = newMavenSession();

        Object result = new PluginParameterExpressionEvaluator(session, exec).evaluate("${plugin}");

        System.out.println("Result: " + result);

        assertSame(
                exec.getMojoDescriptor().getPluginDescriptor(),
                result,
                "${plugin} expression does not return plugin descriptor.");

        return request.getUserProperties();
    }

    /**
     * Gets the system properties to use for interpolation and profile activation. The system properties are collected
     * from the runtime environment like {@link System#getProperties()} and environment variables.
     *
     * @return The system properties, never {@code null}.
     */
    public Properties getSystemProperties() {

        MojoExecution exec = newMojoExecution(session);

        Object result =
                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${mojo.plugin.descriptor}");

        System.out.println("Result: " + result);

        assertSame(
                exec.getPlugin().getDescriptor(),
                result,
                "${mojo.plugin.descriptor} expression does not return plugin descriptor.");

        if (artifact == null) {
            return;
        }

        if (Artifact.SCOPE_SYSTEM.equals(artifact.getScope())) {
            File systemFile = artifact.getFile();

            if (systemFile == null) {
                throw new ArtifactNotFoundException("System artifact: " + artifact + " has no file attached", artifact);
            }

            if (!systemFile.exists()) {

  a coordinated offline strategy. In addition, efforts to unite these failing
  behaviors behind a consistent user interface is much, much more difficult if
  the system can't tell whether it has access to the network required by these
  operations.

  Offline mode really means anticipating a lack of network connectivity, and as