Python type hints for types not yet defined : <p>How do I provide type hints for an alternative constructor for a class? For example if I have a method like this converting something to my new class,</p>

<pre><code>class MyClass:
    @classmethod
    def from_string(cl: Type[????], s: str) -&gt; ????:
        p, q = some_function(s)
        return cl(p, q)
</code></pre>

<p>what should I write for <code>????</code>? It should by nature just be <code>MyClass</code>, but that variable is not defined yet at the time when the method definition is executed.</p>
