human
Complete this python program:
def auth_token_required(fn):
assistant
#Here is the Python code you requested.

    """Decorator that protects endpoints using token authentication. The token
    should be added to the request by the client by using a query string
    variable with a name equal to the configuration value of
    `SECURITY_TOKEN_AUTHENTICATION_KEY` or in a request header named that of
    the configuration value of `SECURITY_TOKEN_AUTHENTICATION_HEADER`
    """
    @wraps(fn)
    def decorated(*args, **kwargs):
        if _check_token():
            return fn(*args, **kwargs)
        if _security._unauthorized_callback:
            return _security._unauthorized_callback()
        else:
            return _get_unauthorized_response()
    return decorated