title: Python type hint given as a string?
body: <p>I have a function of this form:</p>
  
  <pre><code>def foo(o: "hello") -&gt; dict:
      # pass
  </code></pre>
  
  <p>I understand that the "-> dict" means that foo returns a dictionary. What I don't understand is the "hello" part. Why is this type hint given as a string? What is "hello"?</p>
  
  <p>Possibly relevant - this is an autogenerated file.</p>