if (externalRepositories != null) {
            return externalRepositories;
        } else {
            return new ArrayList<>();
        }
    }

    public ProjectRealmCache.CacheRecord createProjectRealm(
            MavenProject project, Model model, ProjectBuildingRequest request) {
        return new ProjectRealmCache.CacheRecord(null, null);
    }

    public void selectProjectRealm(MavenProject project) {}

        }

        artifactRepositories = repositorySystem.getEffectiveRepositories(artifactRepositories);

        return artifactRepositories;
    }

    public synchronized ProjectRealmCache.CacheRecord createProjectRealm(
            MavenProject project, Model model, ProjectBuildingRequest request)
            throws PluginResolutionException, PluginVersionResolutionException, PluginManagerException {
        ClassRealm projectRealm;

                    .thenReturn(logger);

            classRealmManager = newDefaultClassRealmManager(container);
            classRealm = classRealmManager.createProjectRealm(newTestModel(), newTestArtifactList());
        }

        assertEquals(classRealmManager.getMavenApiRealm(), classRealm.getParentClassLoader());

     *            missing file) will automatically be excluded from the realm.
     * @return The new project realm, never {@code null}.
     */
    ClassRealm createProjectRealm(Model model, List<Artifact> artifacts);

    /**
     * Creates a new class realm for the specified build extension.
     *

        if (event.request().isProcessPlugins()) {
            try {
                ProjectRealmCache.CacheRecord record =
                        projectBuildingHelper.createProjectRealm(project, model, projectBuildingRequest);

                project.setClassRealm(record.getRealm());
                project.setExtensionDependencyFilter(record.getExtensionArtifactFilter());

     * @return The record with the project realm and extension artifact filter, never {@code null}.
     * @throws PluginResolutionException If any build extension could not be resolved.
     */
    ProjectRealmCache.CacheRecord createProjectRealm(MavenProject project, Model model, ProjectBuildingRequest request)
            throws PluginResolutionException, PluginVersionResolutionException, PluginManagerException;

    /**

        populateRealm(classRealm, constituents);

        return classRealm;
    }

    public ClassRealm getCoreRealm() {
        return containerRealm;
    }

    public ClassRealm createProjectRealm(Model model, List<Artifact> artifacts) {
        Objects.requireNonNull(model, "model cannot be null");

        ClassLoader parent = getMavenApiRealm();