Optionaloptions: {ReadonlybodyReadonlycontextReadonlyheadersReadonlymethodReadonlyparamsReadonlyreportReadonlyresponseReadonlyurlReadonlyurlReadonlywithTransform the free-form body into a serialized format suitable for transmission to the server.
Examine the body and attempt to infer an appropriate MIME type for it. If no such type can be inferred, this method will return
null.