accessing
messages

	messages ifNil: [ messages := TweetsCollection new ].
	messages ifEmpty: [ self getRemoteMessagesFromHtml ].
	[ config at: 'reportingPeriod' ] 
		onErrorDo: [ self config 
			at: 'reportingPeriod'
			put: (Timespan 
				starting: (messages oldest created asDateAndTime) 
				ending: (messages newest created asDateAndTime + 1 minute)) ].
	^ messages select: [ :message | message created between: self reportingPeriod start and: self reportingPeriod end ]