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Last updated at 9:57 am UTC on 10 October 2019
Class comment:

I am a stand-in for an object that is out on the disk. The object that is out on the disk is the head of a tree of objects that are out. See SqueakPage.

When any message is sent to me, I don't understand it, and bring in my true object. I become myself with the objects and resend the message.

I may not represent the object nil.
The file is represented as a url, and that url may point at any file on the net.

page is a SqueakPage.
If the cache already has an object, widely in use, that claims to be the object for my url, what do I do? I can't become him, since others believe that he is the true object. Run through memory and replace refs to me with refs to him. Be careful not to trigger a fault. Become me to a string, then find pointers and replace?

[[[They don't want to end up holding an ObjectOut. (would oscillate back and forth) This is a problem. A user could bring in two trees that both refer to a 3rd url. (check with cache before installing any new ObjectOut) Two trees could be written to the same url.
Or, I remain an ObjectOut, and keep getting notUnderstood, and keep returning the other guy.
Or I smash the cache, and install MY page and object. Other guy is a copy – still in, but with no place in the cache. When we both write to the same url, there will be trouble.] No – search and replace.]]]