toJson method
Implementation
Map<String, dynamic> toJson() {
var map = <String, dynamic>{'access_token': accessToken};
if (refreshToken?.isNotEmpty == true) map['refresh_token'] = refreshToken;
if (expiresIn != null) map['expires_in'] = expiresIn;
if (scope != null) map['scope'] = scope!.toList();
return map;
}