 
 extension String {
     func toJSON() -> Any? {
-        guard let data = self.data(using: .utf8, allowLossyConversion: false) else { return nil }
-        return try? JSONSerialization.jsonObject(with: data, options: .mutableContainers)
+        guard let data = data(using: .utf8) else { return nil }
+        return try? JSONSerialization.jsonObject(with: data)
     }
 }

            try jwt.verifyExpirationTime()
        }

        guard let authTime = jwt.expirationTime else { throw VerificationError.init(type: .notFound(key: "auth_time"), message: nil) }
        return VerifiedResult(userId: subject, authTime: authTime)
    }


    var userId: String? { return payloadStringValue(with: "user_id") }

    func verifyExpirationTime() throws {
        guard let issuedAtTime = issuedAtTime else { throw VerificationError(type: .notFound(key: "iat"), message: nil) }
        guard let expirationTime = expirationTime else { throw VerificationError(type: .notFound(key: "exp"), message: nil) }
        let now = Date()
        if now < issuedAtTime {
            throw VerificationError(type: .issuedAtTimeIsNotPast,
