   # @param data the session array
   # @returns the nvd3 chart format
   configure_chart: (sessions, href) ->
-    # TODO - add x2axis with hperlinks and orientation top
     chart_cfg = Helpers.configure_chart(sessions, config)
     chart_cfg.xValues =
       config.x.accessor(sess) for sess in sessions


    # Return the graph configuration.
    data: chart_data(resources, config)
    multiSeries: config.y.data.length > 1
    yFormat: decimal_formatter(precision)
    yLabel: config.y.label
    yMaxMin: _.values(chart_y_range)
    color: (d, i) ->
      config.y.data[i].color
    
  # Replaces the given text elements with hyperlinks.
  d3Hyperlink: (element, href, style) ->  
    # The parent node wrapped by D3.


    # @returns the [{key: label, values: coordinates}] nvd3 data
    chart_data = (resources, config) ->
      # @returns the {key, values} pair
      format_data_series = (resources, x_accessor, data_series) ->
        # @returns the graph [x, y] coordinates
        coordinates = (resources, x_accessor, y_accessor) ->
          [x_accessor(rsc), y_accessor(rsc)] for rsc in resources
        
        key: data_series.label
        values: coordinates(resources, x_accessor, data_series.accessor)
        color: data_series.color

      format_data_series(resources, config.x.accessor, ds) for ds in config.y.data
    
