@Override
      public PsiReference @NotNull [] getReferencesByElement(@NotNull PsiElement element,
                                                             @NotNull ProcessingContext context) {
        return new PsiReference[]{new PyDunderSlotsReference((PyStringLiteralExpression)element)};
      }
@Override
      public PsiReference @NotNull [] getReferencesByElement(@NotNull PsiElement element,
                                                             @NotNull ProcessingContext context)