docs: @SuppressWarnings("unchecked")
    public static LbConfig unwrapLoadBalancingConfig(Map<String, ?> lbConfig) {
      if (lbConfig.size() != 1) {
        throw new RuntimeException(
            "There are " + lbConfig.size() + " fields in a LoadBalancingConfig object. Exactly one"
            + " is expected. Config=" + lbConfig);
      }
      String key = lbConfig.entrySet().iterator().next().getKey();
      return new LbConfig(key, getObject(lbConfig, key));
    }