How to use the gillespy2.core.log.critical function in gillespy2

def get_models(full_path, name):
    try:
        with open(full_path, "r") as model_file:
            stochss_model = json.loads(model_file.read())
            stochss_model['name'] = name
            is_ode = stochss_model['defaultMode'] == "continuous"
    except FileNotFoundError as error:
        print(str(error))
        log.critical("Failed to find the model file: {0}".format(error))

    try:
        _model = ModelFactory(stochss_model, is_ode) # build GillesPy2 model
        gillespy2_model = _model.model
    except Exception as error:
        print(str(error))
        log.error(str(error))
        gillespy2_model = None

    return gillespy2_model, stochss_model

def get_models(full_path, name, wkfl_path, is_ode):
    try:
        with open(full_path, "r") as model_file:
            stochss_model = json.loads(model_file.read())
            stochss_model['name'] = name
    except FileNotFoundError as error:
        log.critical("Failed to copy the model into the directory: {0}".format(error))
        open(os.path.join(wkfl_path, 'ERROR'), 'w').close() # update status to error
    
    try:
        _model = ModelFactory(stochss_model, is_ode) # build GillesPy2 model
        gillespy2_model = _model.model
    except Exception as error:
        log.error("GillesPy2 Model Errors: "+str(error))
        gillespy2_model = None
    
    return gillespy2_model, stochss_model