Combine itemBuilder with StickyHeader in Flutter

I'm new to flutter and I want to organise the elements that I get from Firestore in a list with StickyHeaders. I would like to do it with an itemBuilder and the snapshot I get from the database. My problem is the itemBuilder builds each item separately and has to be returned, but StickyHeader needs to have all items added as children.

How can I achieve this? Just as a reference I paste my code without the StickyHeader. buildItemBubble returns a Card Widget.

StreamBuilder(
    stream: buildSnapshots(_filters),
    builder: (context, snapshot) {
        if (!snapshot.hasData)
            return Center(
                child: CircularProgressIndicator(),
            );
        return snapshot.data.documents.length == 0
            ? Center(child: Text('It\s empty here...'))
            : CupertinoScrollbar(
                child: ListView.builder(
                    key: new PageStorageKey('randomkey'),
                    shrinkWrap: true,
                    padding: const EdgeInsets.all(10.0),
                    itemCount: snapshot.data.documents.length,
                    itemBuilder: (ctx, i) =>
                        buildItemBubble(snapshot, i),
                ),
           );
     },
)