dispose method

@override void dispose()

Overwrite to dispose when this object is removed from the tree

Implementation

@override
void dispose() {
  children
    ..forEach((row) {
      row
        ..forEach((element) {
          if (element != this) element.dispose();
        })
        ..clear();
    })
    ..clear();
  childrenBuild
    ..forEach((row) {
      row
        ..forEach((element) {
          if (element != this) element.dispose();
        })
        ..clear();
    })
    ..clear();
  super.dispose();
}