Notice: this will return the defaultdict default value also for keys
        that are not in the configuration, this is a tradeoff to keep the code simple.

def get_last(self, type_, key):
        """
        Notice: this will return the defaultdict default value also for keys
        that are not in the configuration, this is a tradeoff to keep the code simple.
        """
        self._check_type(type_)
        with self._lock:
            return self._config[type_]['last'][key]