     if typeof filterCallback is 'function' or filterCallback is null
       @filterCallback = filterCallback
 
-    filterer ?= @filterer
-    filterCallback ?= @filterCallback
-
     hasItemViews = do =>
       if @subviews.length > 0
         for name of @subviewsByName when name.slice(0, 9) is 'itemView:'

            "no view found for #{item.cid}"

        # Show/hide or mark the view accordingly.
        filterCallback view, included

        # Update visibleItems list, but do not trigger an event immediately.
        @updateVisibleItems view.model, included, false

      for item, index in @collection.models

        # Apply filter to the item.
        included = if typeof @filterer is 'function'
          @filterer item, index
        else
          true

