@Nullable
  static PsiDirectory getResourceBundlePlacementDirectory(ResourceBundle resourceBundle) {
    PsiDirectory containingDirectory = null;
    for (PropertiesFile propertiesFile : resourceBundle.getPropertiesFiles()) {
      if (containingDirectory == null) {
        containingDirectory = propertiesFile.getContainingFile().getContainingDirectory();
      } else if (!containingDirectory.isEquivalentTo(propertiesFile.getContainingFile().getContainingDirectory())) {
        return null;
      }
    }
    LOG.assertTrue(containingDirectory != null);
    return containingDirectory;
  }
@Nullable
  static PsiDirectory getResourceBundlePlacementDirectory(ResourceBundle resourceBundle)