removeAt method
Implementation
void removeAt(int index) {
  _deletedData.add(jsonEncode(_data[index]));
  _data.removeAt(index);
  controller.reload(clearData: false);
}void removeAt(int index) {
  _deletedData.add(jsonEncode(_data[index]));
  _data.removeAt(index);
  controller.reload(clearData: false);
}