createAuthorizeUrl method Null safety

String createAuthorizeUrl()

Generates an Authorization URL

This should be displayed to the user.

Implementation

String createAuthorizeUrl() {
  return baseUrl +
      '/authorize' +
      buildQueryString({
        'client_id': clientId,
        'scope': scopes.join(','),
        'redirect_uri': redirectUri,
        'state': state
      });
}