ProblemDetails
data class ProblemDetails(val type: String = "about:blank", val status: Int? = null, val title: String? = null, val detail: String? = null, val instance: String? = null, val extensions: JsonObject = JsonObject(emptyMap()))(source)
Standard members of an RFC 9457 problem details object. type defaults to about:blank; problem-specific members are retained in extensions.
status is null if the member is absent, is not a JSON number, or is not a valid status code: "If a member's value type does not match the specified type, the member MUST be ignored" (RFC 9457, 3.1), and "Values outside the range 100..599 are invalid" (RFC 9110, 15). Parsing never fails because of it: the member "is only advisory" (RFC 9457, 3.1.2), the status of the response is HttpErrorResponseException.status, and failing would replace the exception for the actual error response.