<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def to_dict(self):
 """Converts a NestedDict instance into a real dictionary. This is needed for places where strict type checking is done. """

        return {key: val.to_dict() if isinstance(val, NestedDict) else val
                for key, val in self.items()}