def test_build_event(self):
        evt = event.build_event("evt_name", arg1="val1", arg2=None)
        assert evt.name == "evt_name"
        assert evt.args == {'arg1': "val1", 'arg2': None}
def days_till_due(self):
        """
        Returns the number of days till the due date. Returns a negative number
        of days when the due date is in the past.
        Returns 0 when the task has no due date.
        """
        due = self.due_date()
        if due:
            diff = due - date.today()
            return diff.days
        return 0