code: def get_below_key_rect(self):
          
  
          key_below = self.row + 1, self.col, self.tab
  
          border_width_bottom = \
              float(self.cell_attributes[self.key]["borderwidth_bottom"]) / 2.0
  
          rect_below = (self.x, self.y+self.height,
                        self.width, border_width_bottom)
          return key_below, rect_below
docs: Returns tuple key rect of below cell