def addEvent(self, event):
        if not callable(event):
            raise ValueError("Events must be callable", event)
        self._events.append(event)
Generate a histogram object and store in the specified attribute.
dataset/ETHPy150Open twisted/imaginary/imaginary/events.py/TransactionalEventBroadcaster.addEvent--crossover with--dataset/ETHPy150Open google/grr/grr/lib/flows/cron/system.py/_ActiveCounter.Save