@Feignclient
public interface MyFeignClient {
    @RequestMapping(value = "test", = RequestMethod.POST, consumes = "application/json")
    ResponseEntity<String> theActualMethod(
            HttpServletRequest request,
            @RequestHeader("firstHeader") String header1,
            @RequestHeader("secondHeader") byte[] header2);
}

java.lang.IllegalStateException: Method has too many Body parameters: public abstract org.springframework.http.ResponseEntity MyFeignClient.theActualMethod(javax.servlet.http.HttpServletRequest,java.lang.String,byte[])