accessing
messages
	messages ifNil: [ messages := TweetsCollection new ].
	messages ifEmpty: [ self getLocalMessages ].
	messages ifEmpty: [ self getRemoteMessagesFromHtml ].
	config at: 'reportingPeriod' ifAbsent: [ ^ messages ].
	"self configureDefaultReportingPeriod."
	^ messages
		select: [ :message | 
			message created
				between: self reportingPeriod start
				and: self reportingPeriod end ]