code: public static Function<Client<RpcRequest, RpcResponse>, CircuitBreakerRpcClient>
      newPerMethodDecorator(Function<String, CircuitBreaker> factory,
                            CircuitBreakerStrategyWithContent<RpcResponse> strategy) {
          return newDecorator(CircuitBreakerMapping.perMethod(factory), strategy);
      }
docs: Creates a new decorator that binds one {@link CircuitBreaker} per RPC method name 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 an RPC method name and creates a new {@link CircuitBreaker}.