@Nullable
  public CustomResourceBundleState removeNonExistentFiles(final VirtualFileManager virtualFileManager) {
    final List<String> existentFiles = ContainerUtil.filter(myFileUrls, url -> virtualFileManager.findFileByUrl(url) != null);
    if (existentFiles.isEmpty()) {
      return null;
    }
    final CustomResourceBundleState customResourceBundleState = new CustomResourceBundleState();
    customResourceBundleState.myFileUrls.addAll(existentFiles);
    customResourceBundleState.myBaseName = myBaseName;
    return customResourceBundleState;
  }
@Nullable
  public CustomResourceBundleState removeNonExistentFiles(final VirtualFileManager virtualFileManager)