   # In this chart most positioning is calculated by us. The D3 sankey plugin is
   # cool but not flexible enough
   Node: class extends Backbone.Model
-    @width: 20
-    @horizontal_spacing: 170
+    width: 20
+    horizontal_spacing: 170
     vertical_margin: 10
 
     initialize: =>

        .attr("fill", (d, i) -> d.get('color') || colors(i))
        .style("stroke", (d, i) -> d3.rgb(d.get('color') || colors(i)).darker(2))
        .style('stroke-width', 1)
        .attr("width", D3.sankey.Node.width)
        .attr("height", (d) => @y d.value())

      nodes.append("svg:text")

        offset += n.value() + margin
      offset

    x_offset: => @get('column') * (@width + @horizontal_spacing)

    # center point of the node. We use it as link anchor point
    x_center: => @x_offset() + @width / 2

    # The height of the node is the sum of the height of its link. Since links
    # are both inbound and outbound, let's use the max size. Ideally the values
