Can't determine if RequestTemplate or Request has a null body

Hi

In the process of updating feign from version 10.2.3 to 10.7.4, I noticed some deprecation in my codebase on internal code dealing with RequestTemplate and Request. The methods RequestTemplate::requestBody has been marked as deprecated and Request::requestBody has been removed.

I'm fine with moving on and building something better obviously but it seems there is no non deprecated replacement to detect a null body in both classes. For example, this simple code will throw a NPE :

    public static void main(String[] args)
    {
        Request.create(HttpMethod.GET,
                       "http://patate.com",
                       Collections.emptyMap(),
                       (Request.Body) null,
                       (RequestTemplate) null)
               .body();
    }

If there is a non nullability constraint in both classes, there should be preconditions in the constructors and clear java documentation for users.

Thanks

Start by inspecting the Request and RequestTemplate APIs around requestBody() and body(), then reproduce the null-body example from the issue. Determine the intended nullability behavior for both classes; done should include consistent handling and clear documentation or preconditions for callers.