# File temp/Graph/Graph.rb, line 391
      def calculate_right_margin
        @border_right = 7
        if key and key_position == :right
          val = keys.max { |a,b| a.length <=> b.length }
          @border_right += val.length * key_font_size * 0.6 
          @border_right += KEY_BOX_SIZE
          @border_right += 10    # Some padding around the box
        end
      end