code: def BeginContact(self, contact):
      if (
          self.env.lander == contact.fixtureA.body
          or self.env.lander == contact.fixtureB.body
      ):
          self.env.game_over = True
      for i in range(2):
          if self.env.legs[i] in [
              contact.fixtureA.body,
              contact.fixtureB.body,
          ]:
              self.env.legs[i].ground_contact = True
  
imports: import math
  import warnings
  from typing import TYPE_CHECKING, Optional
  import numpy
  import gym
  from gym import error, spaces
  from gym.error import DependencyNotInstalled
  from gym.utils import EzPickle, colorize
  from gym.utils.step_api_compatibility import step_api_compatibility
label_desc: Use image node_id 2 for calling the ContactDetector obj's underlying member method code with example usage: obj.BeginContact(contact) without return types