anchor.diff:      for key, node of @nodes
         @sys.pruneNode(key)
       @nodes = {}
  -    @edges = {}
  +    @rels = {}
   
     getSelectedNode: ->
       @selectedNode
  
positive.code:   setFilter: (filter) ->
      @filter = if filter then new RegExp(filter, 'i') else null
  
    setNodesToShow: (n) ->
      @nodesToShow = n
  
    addNodes: (nodes) ->
      return if nodes.length == 0
  
negative.code: 
  initEventSubscribers = (eventBroker, appContext, space, renderer) ->
    eventBroker.subscribe('nodeCountChanged', ->
      space.setNodeCount appContext.getNodeCount()
    )
  
    eventBroker.subscribe('nodeFilterChanged', ->
  