accessing
splitBytimeSpansOf: integerDivisions

	| borders response |
	response := OrderedDictionary new.
	(self timeSpansOf: integerDivisions) doWithIndex: [ :span :i |
		response
			at: span asDatesString
			put: (self select: [ :message | span includes: (message created asDateAndTime)])
	].
	^ response