private static boolean isPropertyRef(@NotNull PsiExpression expression, @NotNull String key, @Nullable String resourceBundleName) {
    if (resourceBundleName == null) {
      return !PropertiesImplUtil.findPropertiesByKey(expression.getProject(), key).isEmpty();
    }
    List<PropertiesFile> propertiesFiles = I18nUtil.propertiesFilesByBundleName(resourceBundleName, expression);
    boolean containedInPropertiesFile = false;
    for (PropertiesFile propertiesFile : propertiesFiles) {
      containedInPropertiesFile |= propertiesFile.findPropertyByKey(key) != null;
    }
    return containedInPropertiesFile;
  }
private static boolean isPropertyRef(@NotNull PsiExpression expression, @NotNull String key, @Nullable String resourceBundleName)