EntityModel enum map key not support

spring-hateoas 1.1.2

code like this

    public enum EnumKey {
        K1,
        K2
    }

    @GetMapping("/test")
    @ResponseBody
    public ResponseEntity<EntityModel<Map<EnumKey,String>>> test() {
        Map<EnumKey,String> map = new HashMap<>();
        map.put(EnumKey.K1,"1");
        map.put(EnumKey.K2,"2");

        return ok(EntityModel.of(map));
    }

error

Could not write JSON: ****Controller$EnumKey incompatible with java.lang.String; nested exception is com.fasterxml.jackson.databind.JsonMappingException: ****Controller$EnumKey incompatible with java.lang.String (through reference chain: org.springframework.hateoas.EntityModel["[anySetter]"]->java.util.HashMap["K2"])

i think hateoas use @JsonAnyGetter and com.fasterxml.jackson.databind.ser.AnyGetterWriter use string key MapSerializer
https://github.com/spring-projects/spring-hateoas/blob/3b1559fc94127cb20d386b5b0a1ba582467f385b/src/main/java/org/springframework/hateoas/EntityModel.java#L135-L140

already use this added enum key serializer

still doesn't work, what is the correct way?

Reproduce the example against spring-hateoas 1.1.2, then inspect EntityModel.java around the @JsonAnyGetter and Jackson's AnyGetterWriter and MapSerializer behavior. Compare the linked Jackson enum-key serializer discussion; done means an EntityModel containing a Map<EnumKey,String> serializes successfully without the reported key-type error.