Chained API for form and multipart data in BodyInserters [SPR-16133] #20681
The ability to build the form inline:
BodyInserters.fromFormData("a", "a1").param("b", "b1", "b2")
Or multipart data:
BodyInserters.fromMultipartData("foo", new Foo()).param("b", new HttpEntity(...))
Each call to param returns an inserter that's ready for use, either by creating a new one with the additional parameter, or by modifying the existing one.
This issue is a sub-task of #20666
Referenced from: commits a58002a