createState method
Create the CellState for this cell.
This method should be overridden by subclasses.
Implementation
@override
MutableCellState<T, MutableCellBase<T>> createState() {
if (_mutableState?.isDisposed ?? true) {
_mutableState = createMutableState(
oldState: key == null ? _mutableState : null
);
}
return _mutableState!;
}