value-provider.cs

public UserTokenValueProvider(string userToken, string issuerToken, IReadTokenService readTokenService)
{
    _userToken = userToken;
    _issuerToken = issuerToken;
    _readTokenService = readTokenService;
}

public async Task<object> GetValueAsync()
{
    try
    {
        var readResult = _readTokenService.ReadToken(_userToken);
        return new UserTokenResult { Username = readResult.Username, TokenState = TokenState.Valid };
    }
    catch (ArgumentNullException)
    {
        // token not provided
        return new UserTokenResult { TokenState = TokenState.Empty };
    }
    catch
    {
        // token was bad
        return new UserTokenResult { TokenState = TokenState.Invalid };
    }
}