         else
           @gquery.future_value()
       if _.isNumber(x) then x else 0.0
+
+    should_show: =>
+      !!@value()
 
     color: => @get('color') || "steelblue"
 


      # update the node label
      @nodes.data(@nodes_excluding_loss, (d) -> d.get('id'))
        .attr("data-tooltip", (d) =>
          h = ""
          for l in d.left_links

        d3.sum(@right_links, (d) -> d.value())
      )

    should_show: =>
      _.any(@left_links, (link) -> link.should_show()) ||
        _.any(@right_links, (link) -> link.should_show())

    # returns an array of the other nodes that belong to the same column. This
    # is used by the +y_offset+ method to calculate the right node position
    siblings: =>
      items = _.groupBy(@view.nodes_excluding_loss, (node) -> node.get('column'))
      items[@get 'column']

    label: => @get('label') || @get('id')
