I’ve shied away from depending on the extensions gem because (1) I’m undecided about whether I should just tell readers to install it everywhere (rather than shlepping it around with s4t-utils), and I’m afraid that having using those methods would mean readers would see them, look them up in Programming Ruby, not find them, and get annoyed or confused. (But is that really any worse than using methods in s4t-utils?) Think about this more.