&quot;<i>it is really tricky to generate these warnings only when people want them</i>&quot;<p>And we&#x27;re back to Perlis&#x27; lollipop.[1]<p>[1] <a href="http:&#x2F;&#x2F;www.cs.yale.edu&#x2F;homes&#x2F;perlis-alan&#x2F;quotes.html#93" rel="nofollow">http:&#x2F;&#x2F;www.cs.yale.edu&#x2F;homes&#x2F;perlis-alan&#x2F;quotes.html#93</a>