code: def _find_ramps(self) -> List[Ramp]:
          
          rampDict = {
              Point2((x, y)): self.pathing_grid[(x, y)] == 0 and self.placement_grid[(x, y)] == 0
              for x in range(self.pathing_grid.width)
              for y in range(self.pathing_grid.height)
          }
  
          rampPoints = {p for p in rampDict if rampDict[p]}  # filter only points part of ramp
          rampGroups = self._find_groups(rampPoints)
          return [Ramp(group, self) for group in rampGroups]
docs: Calculate (self.pathing_grid - self.placement_grid) (for sets) and then find ramps by comparing heights.