code: def login(self):
          
          auth_data = dict()
          auth_data['apikey'] = self.api_key
          auth_data['username'] = self.username
          auth_data['userkey'] = self.account_identifier
  
          auth_resp = requests_util.run_request('post', self.API_BASE_URL + '/login', data=json.dumps(auth_data),
                                                headers=self.__get_header())
  
          if auth_resp.status_code == 200:
              auth_resp_data = self.parse_raw_response(auth_resp)
              self.__token = auth_resp_data['token']
              self.__auth_time = datetime.now()
              self.is_authenticated = True
          else:
              raise AuthenticationFailedException('Authentication failed!')
docs: This method performs the login on TheTVDB given the api key, user name and account identifier.
  
          :return: None