remoteExtension property Null safety
@JsonKey(fromJson: castPlatformMapToDartMap), read / write
Message extension field The message extension field sent by the server is not persisted locally. Only the messages in the chat room contain this field (NIMMessageChatroomExtension)
Implementation
@JsonKey(fromJson: castPlatformMapToDartMap)
Map<String, dynamic>? remoteExtension;