code: def to_absolute(self, x, y):
          
          return x + self.size/2, y + self.size/2
docs: Converts coordinates provided with reference to the center \
          of the canvas (0, 0) to absolute coordinates which are used \
          by the canvas object in which (0, 0) is located in the top \
          left of the object.
  
          :param x: x value in pixels
          :param y: x value in pixels
          :return: None