onResponse method Null safety
The callback will be executed on success.
If you want to continue the response, call
If you want to complete the response with some custom data directly,
you can resolve a Response object with
handler.resolve and other
response interceptor(s) will not be executed.
If you want to complete the response with an error message,
you can reject a DioError object with
void onResponse( Response response, ResponseInterceptorHandler handler, ) => handler.next(response);