private static void addMixin(GrAnnotationMemberValue value, List<? super PsiClass> mixins) {
    if (value instanceof GrReferenceExpression) {
      final PsiElement resolved = ((GrReferenceExpression)value).resolve();
      if (resolved instanceof PsiClass) {
        mixins.add((PsiClass)resolved);
      }
    }
  }
private static void addMixin(GrAnnotationMemberValue value, List<? super PsiClass> mixins)