Implementation
Map<String, dynamic> get json => {
'identifier': identifier,
'name': name,
'publisher': publisher,
'trayImage': trayImage,
'stickers': stickers,
'animatedStickerPack': animatedStickerPack,
'publisherEmail': publisherEmail,
'publisherWebsite': publisherWebsite,
'privacyPolicyWebsite': privacyPolicyWebsite,
'licenseAgreementWebsite': licenseAgreementWebsite,
'iosAppStoreLink': iosAppStoreLink,
'androidPlayStoreLink': androidPlayStoreLink,
}..removeWhere((key, value) => value == null);