[Pharo-users] Defensive programming or not

Cheers all, In trying to fix one of the issues in Pharo, I came to wonder about the prefered style in in dealing with preconditions to methods in Pharo. In the method Random>>nextInt: anInteger - There is a check if anInteger is negative - There is no check that anInteger is anInteger When should I put a guard there, and throw an early warning, and when is it part of the (often implicit pre-condition)? Best, Kasper