title: 'handleListKeyDown', which lacks return-type annotation
body: <pre><code>function handleListKeyDown = useCallback((event: React.KeyboardEvent) {
    if (event.key === 'Tab') {
      event.preventDefault();
      setOpen(false);
    }
  }, [open]);
  </code></pre>
  
  <p>I got error: </p>
  
  <blockquote>
    <p>'handleListKeyDown', which lacks return-type annotation, implicitly
    has an 'any' return type.</p>
  </blockquote>
  
  <p>Which type should I return in order to fulfill TypeScript expectations? </p>