private void appendChosenAnnotationsRoot(
     @NotNull final OrderEntry entry, @NotNull final VirtualFile vFile) {
   if (entry instanceof LibraryOrderEntry) {
     Library library = ((LibraryOrderEntry) entry).getLibrary();
     LOG.assertTrue(library != null);
     final ModifiableRootModel rootModel =
         ModuleRootManager.getInstance(entry.getOwnerModule()).getModifiableModel();
     final Library.ModifiableModel model = library.getModifiableModel();
     model.addRoot(vFile, AnnotationOrderRootType.getInstance());
     model.commit();
     rootModel.commit();
   } else if (entry instanceof ModuleSourceOrderEntry) {
     final ModifiableRootModel model =
         ModuleRootManager.getInstance(entry.getOwnerModule()).getModifiableModel();
     final JavaModuleExternalPaths extension =
         model.getModuleExtension(JavaModuleExternalPaths.class);
     extension.setExternalAnnotationUrls(
         ArrayUtil.mergeArrays(extension.getExternalAnnotationsUrls(), vFile.getUrl()));
     model.commit();
   } else if (entry instanceof JdkOrderEntry) {
     final SdkModificator sdkModificator = ((JdkOrderEntry) entry).getJdk().getSdkModificator();
     sdkModificator.addRoot(vFile, AnnotationOrderRootType.getInstance());
     sdkModificator.commitChanges();
   }
   myExternalAnnotations.clear();
 }
 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();
 }