I represent cached context state within the virtual machine. I have the same format as normal method and block contexts, but my fields are never referenced directly from Smalltalk. Whenever a message is sent to me I will magically transform myself into a real context which will respond to all the usual messages.
I rely on the fact that block and method contexts have exactly the same number of fixed fields.

	testing
	isPseudoContext

	filing out
	definition

	private
	contextCacheDepth contextCacheDepth:

	system primitives	top
	nextObject See Object>>nextObject.

	testing	top
	isPseudoContext

	class initialization	top
	initialize It's tricky to do the necessary stuff with the regular file-in machinery.

	filing out	top
	definition Our superclass is really nil, but this causes problems when we try to become compact after filing in for the first time. Fake the superclass as Object, and repair the situation during class initialisation.

	private	top
	contextCacheDepth Answer the number of entries in the context cache. This requires a little insider knowledge. Not intended for casual use, which is why it's private protocol.
	contextCacheDepth: