code: def login_github(token_path=None, token=None):
      
  
      token = codetools.github_token(token_path=token_path, token=token)
      g = Github(token)
      debug_ratelimit(g)
      return g
docs: Log into GitHub using an existing token.
  
      Parameters
      ----------
      token_path : str, optional
          Path to the token file. The default token is used otherwise.
  
      token: str, optional
          Literal token string. If specified, this value is used instead of
          reading from the token_path file.
  
      Returns
      -------
      gh : :class:`github.GitHub` instance
          A GitHub login instance.