code: def gen_all(self):
          
  
          borderfuncs = [
              self.get_b, self.get_r, self.get_t, self.get_l,
              self.get_tl, self.get_tr, self.get_rt, self.get_rb,
              self.get_br, self.get_bl, self.get_lb, self.get_lt,
          ]
  
          for borderfunc in borderfuncs:
              yield borderfunc()
docs: Generator of all borders