def add_chart(chart_type, options={})
      TwoCellAnchor.new(self, options)
      @anchors.last.add_chart(chart_type, options)
    end
def add_chart(chart_type, options={})
      TwoCellAnchor.new(self, options)
      @anchors.last.add_chart(chart_type, options)
    end
Adds a chart to the drawing.
 @note The recommended way to manage charts is to use Worksheet.add_chart. Please refer to that method for documentation.
 @see Worksheet#add_chart