MessageCollection constructor
      
      MessageCollection({ 
    
- required GroupChannel channel,
- required MessageListParams params,
- required MessageCollectionHandler handler,
- int? startingPoint,
- Chat? chat,
Constructor for MessageCollection.
startingPoint is the reference point for message retrieval in a chat view.
This should be specified as a timestamp(ms) and the default value is max.
Implementation
MessageCollection({
  required GroupChannel channel,
  required MessageListParams params,
  required MessageCollectionHandler handler,
  int? startingPoint,
  Chat? chat,
}) : super(
        channel: channel,
        params: params,
        handler: handler,
        startingPoint: startingPoint ?? SendbirdChat.maxInt,
        chat: chat ?? SendbirdChat().chat,
      ) {
  sbLog.i(StackTrace.current, 'MessageCollection()');
  //+ [DBManager]
  super.chat.dbManager.appendLocalCacheStat(
        useLocalCache: super.chat.chatContext.options.useCollectionCaching,
        useMessageCollection: true,
      );
  //- [DBManager]
  refresh(); // Check
}