docs: async def build_platform(self, cls: Type[Platform], custom_id):
          """
          Build the Facebook platform. Nothing fancy.
          """
  
          from bernard.server.http import router
  
          p = cls()
  
          if custom_id:
              p._id = custom_id
  
          await p.async_init()
          p.on_message(self.fsm.handle_message)
          p.hook_up(router)
          return p