The answer to this question is that I don't invoke change-class -- the environment does it for me. That's the beauty of the environment.

Working with Python, where I have a machine learning model that I want to tweak without retraining has been very instructive for me in reminding me what I would lose without change-class.

On 9 Dec 2020, at 8:55, dbm@refined-audiometrics.com wrote:

Can I ask why you invoke #'CL:CHANGE-CLASS on an object instead of simply creating a new instance of the second class with adequate initialization?