@Nullable
  public static String calcAnnotationValue(@NotNull PsiAnnotation annotation, @NonNls String attr) {
    PsiElement value = annotation.findAttributeValue(attr);
    Object o = CONSTANT_EVALUATION_HELPER.computeConstantExpression(value);
    if (o instanceof String) {
      return (String)o;
    }
    return null;
  }
@Nullable
  public static String calcAnnotationValue(@NotNull PsiAnnotation annotation, @NonNls String attr)