code: def set_legend_position(self, legend_position):
          
          if legend_position:
              self.legend_position = quote(legend_position)
          else:    
              self.legend_position = None
docs: Sets legend position. Default is 'r'.
  
          b - At the bottom of the chart, legend entries in a horizontal row.
          bv - At the bottom of the chart, legend entries in a vertical column.
          t - At the top of the chart, legend entries in a horizontal row.
          tv - At the top of the chart, legend entries in a vertical column.
          r - To the right of the chart, legend entries in a vertical column.
          l - To the left of the chart, legend entries in a vertical column.