def unmap_trigger(self, session, trigger_source, trigger_destination):
        raise NotImplementedError
Returns a list of q_objects which need to go into the having clause
dataset/ETHPy150Open hgrecco/pyvisa/pyvisa/highlevel.py/VisaLibraryBase.unmap_trigger--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/models/sql/query.py/Query.split_having_parts