def cancel(self):
            """Cancels the instances current subscriptions. Setting self.subs1 to
            None removes the reference to the subscription object, causing it's 
            finalizer (__del__) method to be called."""
            self.subs1 = None
            self.subs2 = None
            self.subs3 = None
Cancels the instances current subscriptions. Setting self.subs1 to
            None removes the reference to the subscription object, causing it's 
            finalizer (__del__) method to be called.
recipes/Python/576979_Observer_pattern_implemented_Descriptor/recipe-576979.py