         .enter()
         .append("svg:g")
         .attr("class", (l) -> "link #{l.left.get('id')} #{l.right.get('id')}")
-        .attr("data-cid", (d) -> d.cid) # unique identifier
       # link path
       links.append("svg:path")
         .style("stroke-width", (link) -> link.value())

  #
  View: class extends D3ChartView
    initialize: ->
      namespace = D3.sankey
      namespace.view = this
      @series = @model.series
      @key = @model.get('key')
      # ugly but simple and effective. If the chart key name ends with _2010

    vertical_margin: 10

    initialize: =>
      @right_links = []
      @left_links = []
      @view = @get 'view'

    # vertical position of the top left corner of the node. Adds some margin
    # between nodes
