Rect = {
  x = 0,
  y = 0,
  width = 10,
  height = 20,
  area = function(self)
    return self.width * self.height
  end,
  clone = function(self)
    o = {};
    o.x = self.x;
    o.y = self.y;
    o.width = self.width;
    o.height = self.height;
    o.area = self.area;
    return o
  end
}