 
         @
 
-    # Turn everything off except for the given data series.  Mutates the data.
+    # Turn everything off except for the given data series.
     showOnly: (key)->
         metadata = chart.metadata()
         for d in data


        @

    # Turn everything on.  Mutates the data.
    showAll: ->
        metadata = chart.metadata()
        for d in data

                break
        @

    # Mark a given data series as hidden.
    hide: (keys, flag = true)->
        metadata = chart.metadata()
        if not (keys instanceof Array)
