code: def get_peers_public_keys(self):
          
          with self._lock:
              # Use a generator inside the list comprehension to filter out None
              # values in a single pass
              return [key for key
                      in (self._network.connection_id_to_public_key(peer)
                          for peer
                          in copy.copy(self._peers))
                      if key is not None]
docs: Returns the list of public keys for all peers.