I represent a quad-edge within a subdivision.

	initialize-release
	initialize

	private
	edgeClass

	accessing	top
	classificationColor Return the classification index of the receiver
	classificationIndex Return the classification index of the receiver
	edges
	first
	flags
	flags:
	isBorderEdge
	isBorderEdge:
	isExteriorEdge
	isExteriorEdge:
	isInteriorEdge
	isInteriorEdge:
	timeStamp
	timeStamp:

	initialize-release	top
	initialize

	private	top
	edgeClass

	instance creation	top
	new Answer a new instance of the receiver (which is a class) with no indexable variables. Fail if the class is indexable.