So, I have this class and I use the method addItem to add some item to my cart and itemsCount to have my total items show up in my cart icon in AppBar.

My question is, how the itemsCount is update after I use addItem if itemsCount does not have notifyListeners( )?

The notifyListeners( ) in addItem that update that? The notifyListeners( ) actually update all the methods in class that are being using in all the app?

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