func fetchCovidOverView(completionHandler: @escaping (Result<CityCovidOverview, Error>) -> Void) {
let url = "https://api.corona-19.kr/korea/country/new/"
let param = [
"serviceKey": {API Key}
]
AF.request(url, method: .get, parameters: param)
.responseData(completionHandler: { response in
switch response.result {
case let .success(data):
do {
let decoder = JSONDecoder()
let result = try decoder.decode(CityCovidOverview.self, from: data)
completionHandler(.success(result))
} catch {
completionHandler(.failure(error))
}
case let .failure(error):
completionHandler(.failure(error))
}
})
}