def METHOD_NAME(lockbox_self, loop_self):
    """ if you pass an instance_method of the lockbox, it should take two arguments:
    the instance of the lockbox (self) and the instance of the loop"""
    loop_self.plot.append(green=np.sin(2*np.pi*loop_self.time),
                          red=lockbox_self.pyrpl.rp.sampler.in1)
    if loop_self.n > 100:  # auto-stop after 1000 cycles
        loop_self._clear()