insertToken method
Implementation
Future<Map<String, Map>> insertToken(AccessTokenResponse tknResp) async {
final serTokens = await storage.read(key);
final scopeKey = getScopeKey(tknResp.scope ?? []);
var tokens = <String, Map>{};
if (serTokens != null) {
tokens = Map.from(jsonDecode(serTokens));
}
tokens[scopeKey] = tknResp.toMap();
return tokens;
}