code: function() {
      var maxValue = 0;
      this.sb.graph.eachNode(function(n) {
        var valArray = n.getData('valueArray'),
            acum = 0;
        $.each(valArray, function(v) { 
          acum += +v;
        });
        maxValue = maxValue>acum? maxValue:acum;
      });
      return maxValue;
    }
docs: /*
  Method: getMaxValue
  
  Returns the maximum accumulated value for the stacks. This method is used for normalizing the graph heights according to the canvas height.
  
  Example:
  
  (start code js)
  var ans = pieChart.getMaxValue();
  (end code)
  
  In some cases it could be useful to override this method to normalize heights for a group of PieCharts, like when doing small multiples.
  
  Example:
  
  (start code js)
  will return 100 for all PieChart instances,
  displaying all of them with the same scale
  $jit.PieChart.implement({
  'getMaxValue': function() {
  return 100;
  }
  });
  (end code)