docs: private static ConsistencyLevel downgrade(
        ConsistencyLevel current, int acknowledgements, DriverException original) {
      if (acknowledgements >= 3) {
        return DefaultConsistencyLevel.THREE;
      }
      if (acknowledgements == 2) {
        return DefaultConsistencyLevel.TWO;
      }
      if (acknowledgements == 1) {
        return DefaultConsistencyLevel.ONE;
      }
      // Edge case: EACH_QUORUM does not report a global number of alive replicas
      // so even if we get 0 alive replicas, there might be
      // a node up in some other datacenter, so retry at ONE.
      if (current == DefaultConsistencyLevel.EACH_QUORUM) {
        return DefaultConsistencyLevel.ONE;
      }
      throw original;
    }