Почему параметры, получаемые в add_user из kwargs, принимают значение None?

import psycopg2
from psycopg2 import sql


def connect(func, *args, **kwargs):
    conn = psycopg2.connect(dbname='vk_wparse', user='vk_wparse', password='vk_wparse', host='localhost')
    cursor = conn.cursor()
    conn.autocommit = False
    
    func(conn, cursor, **kwargs)
    
    cursor.close()
    conn.close()
    return 

@connect
def add_user(conn, cursor, *args, **kwargs):
#Выдает None 
    first_name = kwargs.get('first_name')
    last_name = kwargs.get('last_name')
    username = kwargs.get('username')
    id_ = kwargs.get('id_')
    is_bot = kwargs.get('is_bot'),
    language_code = kwargs.get('language_code')
    print(first_name, last_name, username, id_, is_bot, language_code)
    command = f'INSERT INTO tg_user VALUES({first_name}, {last_name}, {username}, {id_}, {is_bot}, {language_code})'
    cursor.execute(command)
    cursor.commit()

    return 
    введите сюда код