jsonserialization.jsonobject不接受我的参数

我试图承诺一个json对象。

但是,jsonserialization.jsonobject不接受我的任何参数。

class func deserialize<T>(data: Data) -> Promise<T> {
    let deserialized = try! JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments)
        String(data: data, encoding: String.Encoding.utf8)

    // Deserialize or try as String
    guard let object = deserialized else {
        return Promise<T>(error: APIError.InvalidJSON(data) as Error)
    }

    // Cast as T
    guard let objectT = object as? T else {
        return Promise<T>(error: APIError.JSONTypeMismatch(object, T.self))
    }

    return Promise(objectT)
}

我收到两个错误:

let desserialized = try! JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments)

不能用类型为(with:data,options:jsonserialization.readingoptions)的参数列表调用“jsonobject”

String(data: data, encoding: String.Encoding.utf8)

“无法将'data'类型的值转换为所需的参数类型'data'”