I had to make selfet (which contains the implementation of AutoExecThread) to be temporarily private because the multi-agent framework needed a little refactoring. Just turned back the visibility to public.
In that refactoring, the AutoExecThread is defined here: selfet/src/backend/bmodels/threads/main.py at main · icdev2dev/selfet · GitHub
Obviously this, in context of the overall post, is merely illustrative. You might want to look at the implementation of AutoExecThread and roll your own by using the betaassi framework.