code: def furthest(self, ps: Union["Units", List["Point2"], Set["Point2"]]) -> Union["Unit", "Pointlike"]:
          
          assert ps
          if len(ps) == 1:
              return ps[0]
          furthest_distance_squared = -math.inf
          for p2 in ps:
              p2pos = p2
              if not isinstance(p2pos, Point2):
                  p2pos = p2.position
              distance = (self[0] - p2pos[0]) ** 2 + (self[1] - p2pos[1]) ** 2
              if furthest_distance_squared < distance:
                  furthest_distance_squared = distance
                  furthest_element = p2
          return furthest_element
docs: This function assumes the 2d distance is meant