Grouped Sencha List to show only 2 items

gistfile1.coffee

Ext.define 'groupedlist.store.Stories'
  extend:'Ext.data.Store'

	config:
		model:'groupedlist.model.Story'
		autoLoad:false

		grouper:
			groupFn:(record)->
				return record.get("section_name")
		filters:
			filterFn:(record)->
				groups = store.getGroups()
				group = record.get('section_name');

				# for sections that do no exist in the group
				sectionGroupExists = false

				# loop over available groups
				for k,v of groups
					if v.name == group
						sectionGroupExists = true
						if (v.children.length < 2)
							return group

				# if the section does not exist, return the record to populate
				if !sectionGroupExists
					return group