defect
If you pass a JSON object via a POST request, it is not specified in the request's Content-Type header. This may cause the request to fail.
Workaround
In this case, you can—or must—explicitly configure a header parameter and include, for example, "application/json" as a constant value.
Improvement
It’s nice that you can explicitly specify the Content-Type, but if you don’t, “application/json” should be set as the Content-Type by default when a JSON object is included in the request body.
Test
No test