listView method Null safety

Implementation

Widget listView() {
  if (jusoVM.jusoList.length == 0) {
    return Container(
      alignment: Alignment.center,
      color: Colors.white,
      child: Column(
        children: [
          Container(height: 15, color: Color(0xFFEdEdEd)),
          Expanded(child: Center(child: Text(jusoVM.errorMessage))),
        ],
      ),
    );
  }

  return Scrollbar(
      child: ListView.builder(
    controller: scrollCon,
    itemCount: jusoVM.jusoList.length + 1,
    itemBuilder: (BuildContext context, int index) {
      print("index: $index");
      if (index == 0) return Container(height: 15, color: Color(0xFFEdEdEd));
      if (index == jusoVM.jusoList.length) addAddressList();

      final address = jusoVM.jusoList[index - 1];
      return Column(
        children: [
          listItem(address),
          Container(height: 1, color: Color(0xFFEdEdEd)),
        ],
      );
    },
  ));
}