accessing
repliesByWeeksTimeSpan

	| tweetsByTimeSpan xAxis labels |
	self replies isEmpty
		ifTrue: [ ^ { OrderedDictionary new. 
			('[''', '0', ''']'). 
			('[''', 'No replies', ''']')} ].
	tweetsByTimeSpan := self collectMessages: [ self replies ] byTimeSpanSplits: self tweetsDivisionsByWeeks.
	xAxis := OrderedCollection new.
	(tweetsByTimeSpan values collect: [ :collection | collection size ]) do: [ :number |
							xAxis add: ($' asString), (number asString), ($' asString)
																			].
	labels := OrderedCollection new.
	tweetsByTimeSpan keys do: [ :string |
		labels add: ($' asString), string, ($' asString)
							].
	^ {
	tweetsByTimeSpan.
	('[', (',' join: xAxis), ']').
	('[', (',' join: labels), ']').
	}