Third Party How to use interface as value of Mirror's SyncDictionary?

Is there a way I can avoid storing durability or enchantment level for any item i.e. health potions or a fruit?

My initial relevant code piece:

Code (CSharp):

1. [System.Serializable]
2.     public struct ItemData
3.     {
4.         public uint ID;
5.         public long Count;
6.  
7.         public ItemData(uint newID, long newCount)
8.         {
9.             ID = newID;
10.             Count = newCount;
11.         }
12.     }
13.  
14. [System.Serializable]
15.     public class SyncDictionaryInventoryData : SyncDictionary<int, ItemData> { }
16.  
17.     [System.Serializable]
18.     public class SyncDictionaryEquipmentData : SyncDictionary<EquipmentSlot, ItemData> { }

Then I wanted to add Durability and Enchantment data and
my new code piece became:

Code (CSharp):

1. public interface IItemData
2.     {
3.         public uint ID { get; set;  }
4.         public long Count { get; set; }
5.     }
6.  
7.     [System.Serializable]
8.     public struct ItemData : IItemData
9.     {
10.         public uint ID { get; set; }
11.         public long Count { get; set; }
12.  
13.         public ItemData(uint newID, long newCount)
14.         {
15.             ID = newID;
16.             Count = newCount;
17.         }
18.     }
19.  
20.     [System.Serializable]
21.     public struct EquipData : IItemData
22.     {
23.         public uint ID { get; set; }
24.         public long Count { get; set; }
25.         public short Durability { get; set; }
26.         public short Enchantment { get; set; }
27.  
28.         public EquipData(uint newID, long newCount, short newDurability, short newEnchantment)
29.         {
30.             ID = newID;
31.             Count = newCount;
32.             Durability = newDurability;
33.             Enchantment = newEnchantment;
34.         }
35.     }
36.  
37. [System.Serializable]
38.     public class SyncDictionaryInventoryData : SyncDictionary<Vector2Byte, IItemData> { }
39.  
40.     [System.Serializable]
41.     public class SyncDictionaryEquipmentData : SyncDictionary<EquipmentSlot, EquipData> { }

But this gives errors like:
"(0,0): error Cannot generate writer for interface IItemData. Use a supported type or provide a custom writer (at Inventory.IItemData)"

 

Solved, just use nullable fields.