Polymorphic property with RavenDB

RavenDb_PolymorphicProperty

public class Listing
  {
    public string Id { get; set; }
    public string Name { get; set; }
    public AdditionalInfo Info { get; set; }
  }

  public abstract class AdditionalInfo
  {
  }

  class AdditionalInfoForPark : AdditionalInfo
  {
    public string[] Amenities { get; set; }
  }

  class AdditionalInfoForEvent : AdditionalInfo
  {
    public DateTime Start { get; set; }
    public DateTime End { get; set; }
  }