I would have leaned toward calling this a Useful Note, but the writer has chosen to call it a Trope (commenting out the Useful Notes tag). I can see arguments either way.
If it's a trope, it needs examples in fiction... and, amazingly enough, Wikipedia has a list that we can use as a starting point with appropriate credit. EDIT: Although that page has both Examples and Shout-Outs, so we can't just copy it over as-is.