def get_replicas(self, keyspace, key):
        """
        Returns a list of :class:`.Host` instances that are replicas for a given
        partition key.
        """
        t = self.token_map
        if not t:
            return []
        try:
            return t.get_replicas(keyspace, t.token_class.from_key(key))
        except NoMurmur3:
            return []