@Override
    public HystrixCommand.Setter create(Target<?> target, Method method) {
      String groupKey = target.name();
      String commandKey = Feign.configKey(target.type(), method);
      return HystrixCommand.Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey(groupKey))
          .andCommandKey(HystrixCommandKey.Factory.asKey(commandKey));
    }
Default behavior is to derive the group key from {@link Target#name()} and the command key from
{@link Feign#configKey(Class, Method)}.
hystrix/src/main/java/feign/hystrix/SetterFactory.java