code: public static Function<Client<RpcRequest, RpcResponse>, CircuitBreakerRpcClient>
      newPerHostDecorator(Function<String, CircuitBreaker> factory,
                          CircuitBreakerStrategyWithContent<RpcResponse> strategy) {
          return newDecorator(CircuitBreakerMapping.perHost(factory), strategy);
      }
docs: Creates a new decorator that binds one {@link CircuitBreaker} per host with the specified
  {@link CircuitBreakerStrategy}.
  
  <p>Since {@link CircuitBreaker} is a unit of failure detection, don't reuse the same instance for
  unrelated services.
  
  @param factory a function that takes a host name and creates a new {@link CircuitBreaker}