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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def nodes(self):
 """Set of all currently connected servers. .. warning:: When connected to a replica set the value of :attr:`nodes` can change over time as :class:`MongoClient`'s view of the replica set changes. :attr:`nodes` can also be an empty set when :class:`MongoClient` is first instantiated and hasn't yet connected to any servers, or a network partition causes it to lose connection to all servers. """

        description = self._topology.description
        return frozenset(s.address for s in description.known_servers)