def __init__(self, signum):
        Event.__init__(self)
        self.signum = signum
        self.rearm()
Validate reference.
dataset/ETHPy150Open dieseldev/diesel/diesel/util/event.py/Signal.__init__--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/db/__init__.py/ReferenceProperty.validate