Compressing POST requests in flutter

main.dart

void sendCompressed() async {
  var gzip = GZipCodec();

    String jsonToSend = '{"field1":"Some JSON to send to the server."}';
    var compressedBody = gzip.encode(jsonToSend.codeUnits);
    Map<String, String> headers = { 
      "Content-Encoding": "gzip", 
      "Content-Type": "application/json; charset=UTF-8",
    };
    var response = await http.post( 
      "https://example.com/api/v1", 
      headers,     
      compressedBody );
}