code: async def valid_token_set(self):
          
          is_valid = False
  
          if self._auth_client.token:
              # Account for a token near expiration
              now = datetime.datetime.utcnow()
              skew = datetime.timedelta(seconds=60)
              if self._auth_client.expiry > (now + skew):
                  is_valid = True
          return is_valid
docs: Check for validity of token, and refresh if none or expired.