Widget _buildCardCollapse(BuildContext context) { return TDCollapse( style: TDCollapseStyle.card, expansionCallback: (int index, bool isExpanded) { setState(() { _cardStyleData[index].isExpanded = !isExpanded; }); }, children: _cardStyleData.map((CollapseDataItem item) { return TDCollapsePanel( headerBuilder: (BuildContext context, bool isExpanded) { return Text(item.headerValue); }, isExpanded: item.isExpanded, body: const Text(randomString), ); }).toList(), ); }