def set_exp(
        self,
        claim: str = "exp",
        from_time: Optional[datetime] = None,
        lifetime: Optional[timedelta] = None,
    ) -> None:
        """
        Updates the expiration time of a token.

        See here:
        https://tools.ietf.org/html/rfc7519#section-4.1.4
        """
        if from_time is None:
            from_time = self.current_time

        if lifetime is None:
            lifetime = self.lifetime

        self.payload[claim] = datetime_to_epoch(from_time + lifetime)

        Updates the expiration time of a token.

        See here:
        https://tools.ietf.org/html/rfc7519#section-4.1.4
        
rest_framework_simplejwt/tokens.py