1. Engineers built toilets, which are very useful for the disposing of wee.
Imagine what would happen if your toilet was not correctly tested.
It may have had a bug in it that caused you to piss in your face!
:@
2. It's the same in any non-shit language. Look:
code:
sendEmail(to,from,subject,...)
vs
code:
saveVariable(content,...)
if (mode = live)
sendEmail(to,from,subject,content)
else
writeFile(content)