def draw_shape(im, location, shape_name=:circle, shape_parameters= 10)

      if self.respond_to?(shape_name) then

        self.send(shape_name, im, location, shape_parameters)

      end

    end
def draw_shape(im, location, shape_name=:circle, shape_parameters= 10)

      if self.respond_to?(shape_name) then

        self.send(shape_name, im, location, shape_parameters)

      end

    end
Draws a specified shape into an image.

 @param [WritableImage] im the image into which to draw
 @param [Array] location an array containing the coordinates of the shape to draw.
  The exact meaning of this parameter depends on which shape is being drawn.
 @param [Symbol] shape_name the name of the shape to draw.  This should correspond
  to one of the methods of this class.
 @param shape_parameters the parameters for drawing the specified shape;
  the meaning of this parameter depends on the shape.

 @return [void]