def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def __init__(self, signum, signame):
            self.signum = signum
            self.signame = signame
            self.traceback_lines = traceback.format_stack()
            super(SignalHandler.SignalHandledNonLocalExit, self).__init__()