code: def unit_alias(self) -> Optional[UnitTypeId]:
          
          if self._proto.unit_alias == 0:
              return None
          if self._proto.unit_alias not in self._game_data.units:
              return None
          """ For flying OrbitalCommand, this returns UnitTypeId.OrbitalCommand """
          return UnitTypeId(self._proto.unit_alias)
docs: Building type equality, e.g. FlyingOrbitalCommand is the same as OrbitalCommand