<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get(self, key, default):
 """If the key is set, return a copy of the list stored at key. Otherwise return default."""

        with self._lock:
            try:
                return self._dict[key].copy()
            except KeyError:
                return default