Instance method 'METHOD' requires that 'CLASS' conform to 'PROTOCOL' problem

🎤 General Discussion Swift
1

I’m trying to create a method to insert relationship into Core Data using Generics but I’ve problem with generics:
below there is the code that I’ve written.

Can you help me to fix it?

let lista = kanji.map{($0.kunYomi)} // let lista: [[KunYomi]]
let batchInsert2 = createBatchInsertRelationshipRequest(from: lista[0], for: KunYomi.self) // Here is the error Instance method 'createBatchInsertRelationshipRequest(from:for:)' requires that 'KunYomi' conform to 'BatchInsertable'


private func createBatchInsertRelationshipRequest<T:BatchInsertable, E:NSManagedObject>(from relationshipCollection:[T], for type:E.Type) -> NSBatchInsertRequest {
        var index = 0
        var total = relationshipCollection.count
        
        let batchInsertRequest = NSBatchInsertRequest(entity: E.entity(), dictionaryHandler: { dictionary in
            guard index < total else { return true }
            dictionary.addEntries(from: relationshipCollection[index].dictionaryValue as [AnyHashable: Any])
            index += 1
            return false
        })
        return batchInsertRequest
    }

public struct KunYomi:BatchInsertable{
    public let id:Int16
    public let kunYomiKanji:String
    public let kunYomiKana:String
    public let kunYomiRomaji:String
    public let kunYomiRomaji1:String
    public let idKanji:Int16
    
    enum CodingKeys:String, CodingKey{
        case id = "id"
        case kunYomiKanji   = "kun_yomi_kanji"
        case kunYomiKana    = "kun_yomi_kana"
        case kunYomiRomaji  = "kun_yomi_romaji"
        case kunYomiRomaji1 = "kun_yomi_romaji_1"
        case idKanji        = "id_kanji"
    }
    
    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.id = Int16( try container.decode(String.self, forKey: .id)) ?? 0
        self.kunYomiKanji = try container.decode(String.self, forKey: .kunYomiKanji)
        self.kunYomiKana = try container.decode(String.self, forKey: .kunYomiKana)
        self.kunYomiRomaji = try container.decode(String.self, forKey: .kunYomiRomaji)
        self.kunYomiRomaji1 = try container.decode(String.self, forKey: .kunYomiRomaji1)
        self.idKanji = Int16( try container.decode(String.self, forKey: .idKanji)) ?? 0
    }
    
    var dictionaryValue: [String : Any] {
        ["id":id as Any,
         "kunYomiKanji":kunYomiKanji as Any,
         "kunYomiKana":kunYomiKana as Any,
         "kunYomiRomaji":kunYomiRomaji as Any,
         "kunYomiRomaji1":kunYomiRomaji1 as Any,
         "idKanji":idKanji as Any
        ]
    }
}

protocol BatchInsertable:Codable {
    var dictionaryValue:[String:Any] { get }
}