def METHOD_NAME(self, par_setpoint, epoch):
    """warmup.
    start from a small value of par to ramp up the steady state value using
    # total_steps
    :param epoch:
    """
    ratio = ((epoch+1) * 1.) / self.total_steps
    list_par = [par_setpoint, par_setpoint * ratio]
    par = min(list_par)
    return par