public static void addSourceRoot(
     final ModuleRootManager manager, @NotNull final VirtualFile root) {
   final ModifiableRootModel model = manager.getModifiableModel();
   ContentEntry contentEntry = findContentEntryForRoot(model, root);
   if (contentEntry == null) {
     contentEntry = model.addContentEntry(root);
   }
   contentEntry.addSourceFolder(root, false);
   model.commit();
 }
  @Override
  public List<Module> commit(
      @NotNull Project project,
      @Nullable ModifiableModuleModel moduleModel,
      @NotNull ModulesProvider modulesProvider,
      @Nullable ModifiableArtifactModel modifiableArtifactModel) {
    Set<String> selectedAppNames = ContainerUtil.newHashSet();
    for (ImportedOtpApp importedOtpApp : mySelectedOtpApps) {
      selectedAppNames.add(importedOtpApp.getName());
    }
    Sdk projectSdk = fixProjectSdk(project);
    List<Module> createdModules = new ArrayList<Module>();
    final List<ModifiableRootModel> createdRootModels = new ArrayList<ModifiableRootModel>();
    final ModifiableModuleModel obtainedModuleModel =
        moduleModel != null ? moduleModel : ModuleManager.getInstance(project).getModifiableModel();
    for (ImportedOtpApp importedOtpApp : mySelectedOtpApps) {
      VirtualFile ideaModuleDir = importedOtpApp.getRoot();
      String ideaModuleFile =
          ideaModuleDir.getCanonicalPath() + File.separator + importedOtpApp.getName() + ".iml";
      Module module =
          obtainedModuleModel.newModule(ideaModuleFile, ErlangModuleType.getInstance().getId());
      createdModules.add(module);
      importedOtpApp.setModule(module);
      if (importedOtpApp.getIdeaModuleFile() == null) {
        ModifiableRootModel rootModel = ModuleRootManager.getInstance(module).getModifiableModel();
        // Make it inherit SDK from the project.
        rootModel.inheritSdk();
        // Initialize source and test paths.
        ContentEntry content = rootModel.addContentEntry(importedOtpApp.getRoot());
        addSourceDirToContent(content, ideaModuleDir, "src", false);
        addSourceDirToContent(content, ideaModuleDir, "test", true);
        addIncludeDirectories(content, importedOtpApp);
        // Exclude standard folders
        excludeDirFromContent(content, ideaModuleDir, "doc");
        // Initialize output paths according to Rebar conventions.
        CompilerModuleExtension compilerModuleExt =
            rootModel.getModuleExtension(CompilerModuleExtension.class);
        compilerModuleExt.inheritCompilerOutputPath(false);
        compilerModuleExt.setCompilerOutputPath(ideaModuleDir + File.separator + "ebin");
        compilerModuleExt.setCompilerOutputPathForTests(ideaModuleDir + File.separator + ".eunit");
        createdRootModels.add(rootModel);
        // Set inter-module dependencies
        resolveModuleDeps(rootModel, importedOtpApp, projectSdk, selectedAppNames);
      }
    }
    // Commit project structure.
    LOG.info("Commit project structure");
    ApplicationManager.getApplication()
        .runWriteAction(
            new Runnable() {
              public void run() {
                for (ModifiableRootModel rootModel : createdRootModels) {
                  rootModel.commit();
                }
                obtainedModuleModel.commit();
              }
            });

    addErlangFacets(mySelectedOtpApps);
    RebarSettings.getInstance(project).setRebarPath(myRebarPath);
    if (myIsImportingProject) {
      ErlangCompilerSettings.getInstance(project).setUseRebarCompilerEnabled(true);
    }
    CompilerWorkspaceConfiguration.getInstance(project).CLEAR_OUTPUT_DIRECTORY = false;

    return createdModules;
  }