HasMany relationship treated as HasOne in deserialization

[jfhs]

Having a model

    public class Country: Identifiable<Guid>
    {
        [Attr("name")]
        public string Name { get; set; }

        [HasMany("cities")]
        public virtual List<City> Cities { get; set; }
    }

And trying to post

{"data": {
    "attributes": {
      "name":"qwe"
    },
    "relationships": {
      "cities": {
        "data": []
      }
    },
    "type":"countries"
  }
}

JsonApiDeSerializer tries to find CitiesId property in here which it of course doesn't.

I believe there should be separate code for handling HasMany relationships.