On Fri, Oct 25, 2013 at 10:58:49PM +0000, commits at source.squeak.org wrote:
> 
> Item was changed:
>   Object subclass: #DeepCopier
>   	instanceVariableNames: 'references uniClasses newUniClasses'
> + 	classVariableNames: ''
> - 	classVariableNames: 'NextVariableCheckTime'
>   	poolDictionaries: ''
>   	category: 'System-Object Storage'!

One thing that I find rather appealing about Squeak is that its stew of
living objects contains things that have existed since before my time.
Even if the so-called "code" changes, the objects still can survive.

Every once in a while this turns out to have some practical benefit. For
example, the class DeepCopier had a class variable that kept track of some
sort of time stamp (in the form of NextVariableCheckTime seconds). Some
time in an earlier millenium, a primeval user of the class had set this
variable, then wandered off into a tar pit. We do not really know who that
may have been, but the original object (class DeepCopier) has survived in
the image, and the last updated value of its NextVariableCheckTime has
remained undisturbed since those early days. Thus when I became curious
about whether this class variable was being used, I was able to look at
its value and convert it to a DateAndTime to see that it had not been
updated in the last dozen years or so.

It's a small thing, but just try keeping track of that with a version
control system.

Dave