code: def test_get_lb_policy_no_host_for_allow_list(self):
      # test host not specified for WhiteListRoundRobinPolicy should throw exception
      self._assert_get_lb_policy(
          "WhiteListRoundRobinPolicy",
          {},
          WhiteListRoundRobinPolicy,
          should_throw=True,
      )
      self._assert_get_lb_policy(
          "TokenAwarePolicy",
          {"child_load_balancing_policy": "WhiteListRoundRobinPolicy"},
          TokenAwarePolicy,
          expected_child_policy_type=RoundRobinPolicy,
          should_throw=True,
      )
  
imports: from __future__ import annotations
  import re
  from unittest import mock
  import pytest
  from cassandra.cluster import Cluster
  from cassandra.policies import DCAwareRoundRobinPolicy, RoundRobinPolicy, TokenAwarePolicy, WhiteListRoundRobinPolicy
  from airflow.models import Connection
  from airflow.providers.apache.cassandra.hooks.cassandra import CassandraHook
  from airflow.utils import db
label_desc: Use image node_id 6 for calling the TestCassandraHook obj's underlying member method code with example usage: obj.test_get_lb_policy_no_host_for_allow_list() without return types