I'm writing a class (which I'm calling MutableTime) that is like a Time
object, but...well...mutable :) Changeable in all sorts of magical ways.
I'd like it to have almost all the methods of Time, so this seems like a
clear case for inheritance:
class MutableTime < Time
However, I've run into cases where I want to modify some internal values
of the instance, and (since Time is written in C) I can't figure out
what private instance variables I may or may not have access to.
For example, I want to let the user change the year: