code: def main_base_ramp(self) -> "Ramp":
          
          if hasattr(self, "cached_main_base_ramp"):
              return self.cached_main_base_ramp
          self.cached_main_base_ramp = min(
              {ramp for ramp in self.game_info.map_ramps if len(ramp.upper2_for_ramp_wall) == 2},
              key=(lambda r: self.start_location.distance_to(r.top_center)),
          )
          return self.cached_main_base_ramp
docs: Returns the Ramp instance of the closest main-ramp to start location. Look in game_info.py for more information