{

  "title":{
    "text":"Test stacked bar charts",
    "style":"{font-size:16px;}"
  },

  "elements":[
    {
      "type":      "bar_stack",
      "colour":    "#FFB900",
      "text":      "Stack",
      "font-size": 10,
      "tip":       "#total#<br>(bar total)",
      "values": [
        [2.5,{"val":5}],
        [{"val":2.5},{"val":5},{"val":2.5}],
        null,
        [{"val":5},{"val":5},{"val":2},{"val":2},{"val":2,"colour":"#ff00ff","tip":"hello"},{"val":2},{"val":2}]
        ]
    },
    {
      "type":      "bar",
      "colour":    "#9933CC",
      "text":      "Bar",
      "font-size": 10,
      "values" :   [9,6,7,9]
    }
  ],

  "x_axis":{
    "max":4,
    "steps": 1,
    "labels": {
      "labels": ["January","February","March","April"]
    },
    "stroke": 12,
    "tick-height": 6
  },

  "y_axis":{
    "max": 20
  }
}