Do you mean decorators? A solution like that exists and has been used for a while. It really is only usable for run-time type-checks. See here: <a href="https:&#x2F;&#x2F;github.com&#x2F;dobarkod&#x2F;typedecorator" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;dobarkod&#x2F;typedecorator</a><p>With type annotations you can have static guarantees, which decorators will not be able to provide, as decorator methods will be called and resolved only during runtime. Objects imported from `types` hopefully will not.