No comment. Sorry.

	initialization
	initialize:

	printing
	printOn:

	private
	object:

	accessing	top
	atForward:put:
	forward:
	level
	next
	object

	initialization	top
	initialize:

	printing	top
	printOn: Append to the argument, aStream, a sequence of characters that identifies the receiver.

	private	top
	object:

	instance creation	top
	new: Answer an instance of this class with the number of indexable variables specified by the argument, sizeRequested.
	on:level:
	tailOfLevel: