Hello, I d like to use a custom function for a filter in a schedule's clock. using my own lambda or script defined function throws an error of serialization: prefect/utilities/serialization.py", line 397, in _serialize raise ValidationError("Invalid function reference: {}".format(value)) marshmallow.exceptions.ValidationError: Invalid function reference: <function mon_sat_day_filter at 0x7f35e22d78b0> Is there a way around this ? Is there away to interpret a list of filter funcs with OR condition rather than AND ? For reference, Iam trying to run a job Mon - Sat, so an OR condition on a list of is_day_of_week filter func would do. Thank you!