code: def quad_tree(self):
          
          value = ''
          tms_x, tms_y = self.tms
          tms_y = (2 ** self.zoom - 1) - tms_y
          for i in range(self.zoom, 0, -1):
              digit = 0
              mask = 1 << (i - 1)
              if (tms_x & mask) != 0:
                  digit += 1
              if (tms_y & mask) != 0:
                  digit += 2
              value += str(digit)
          return value
docs: Gets the tile in the Microsoft QuadTree format, converted from TMS