    # File lib/prawn/graphics.rb, line 180
        def ellipse_at(point, r1, r2 = r1)
          x, y = point
          l1 = r1 * KAPPA
          l2 = r2 * KAPPA

          move_to(x + r1, y)

          # Upper right hand corner
          curve_to [x,  y + r2],
            :bounds => [[x + r1, y + l1], [x + l2, y + r2]]

          # Upper left hand corner
          curve_to [x - r1, y],
            :bounds => [[x - l2, y + r2], [x - r1, y + l1]]

          # Lower left hand corner
          curve_to [x, y - r2],
            :bounds => [[x - r1, y - l1], [x - l2, y - r2]]

          # Lower right hand corner
          curve_to [x + r1, y],
            :bounds => [[x + l2, y - r2], [x + r1, y - l1]]

          move_to(x, y)
        end