CardModelService.swift

struct CardModel {}
protocol CardModelService {
    func fetchCardModels(completion: @escaping (Result<[CardModel], Error>) -> Void)
}

class HomeService: CardModelService {
    
    static let shared = HomeService()
    private init() {}
    
    func fetchCardModels(completion: @escaping (Result<[CardModel], Error>) -> Void) {
        // ...
    }
}

class CartService: CardModelService {
    
    static let shared = CartService()
    private init() {}
    
    func fetchCardModels(completion: @escaping (Result<[CardModel], Error>) -> Void) {
        // ...
    }
}

class ProfileService: CardModelService {
    static let shared = ProfileService()
    private init() {}
    
    func fetchCardModels(completion: @escaping (Result<[CardModel], Error>) -> Void) {
        // ...
    }
}