message: docs(http): add information about body content type to flush method for testing
  PR Close
diff: @@ -33,6 +33,8 @@ export class TestRequest {
  /**
  * Resolve the request by returning a body plus additional HTTP information (such as response
  * headers) if provided.
  + * If the request specifies an expected body type, the body is converted into the requested type.
  + * Otherwise, the body is converted to `JSON` by default.
  *
  * Both successful and unsuccessful responses can be delivered via `flush()`.
  */
  