getCoinsChart method Null safety

Future<CoinsPriceResponse> getCoinsChart(
  1. String currency,
  2. int nbDays
)

Implementation

Future<CoinsPriceResponse> getCoinsChart(String currency, int nbDays) async {
  CoinsPriceResponse? coinsPriceResponse;
  final HttpClient httpClient = HttpClient();
  try {
    final HttpClientRequest request = await httpClient.getUrl(Uri.parse(
        'https://api.coingecko.com/api/v3/coins/uniris/market_chart?vs_currency=' +
            currency +
            '&days=' +
            nbDays.toString()));
    request.headers.set('content-type', 'application/json');
    final HttpClientResponse response = await request.close();
    if (response.statusCode == 200) {
      final String reply = await response.transform(utf8.decoder).join();
      coinsPriceResponse = coinsPriceResponseFromJson(reply);
    }
  } finally {
    httpClient.close();
  }
  return coinsPriceResponse!;
}