def load(self, policy_file):
        """
        Loads dialogue_policy file.

        :param policy_file: path to the dialogue_policy file
        :return:
        """
        if isinstance(policy_file, str):
            if os.path.isfile(policy_file):
                with open(policy_file, 'rb') as file:
                    obj = pickle.load(file)

                    if 'dialogue_policy' in obj:
                        self.policy = obj['dialogue_policy']

                    print('Dact-to-Language user Simulator policy loaded.')

            else:
                print('Warning! Dact-to-Language policy file %s not found'
                      % policy_file)
        else:
            print('Warning! Unacceptable value for DTL Simulator policy file '
                  'name: %s ' % policy_file)

        Loads dialogue_policy file.

        :param policy_file: path to the dialogue_policy file
        :return:
        
plato/agent/component/user_simulator/dact_to_language_user_simulator/dtl_user_simulator.py