set method
Implementation
set(bool e){
open = e;
that1.forEach((el) { el.changeOpenState(e); });
that2.forEach((el) { el.changeOpenState(e); });
}
set(bool e){
open = e;
that1.forEach((el) { el.changeOpenState(e); });
that2.forEach((el) { el.changeOpenState(e); });
}