joinWith method
Implementation
List<Widget> joinWith(Widget item)
{
if (this == null) {
return List.empty();
}
List<Widget> ret = [];
for (int i = 0; i < this!.length; i++) {
ret.add(this![i]);
if (i < this!.length - 1) {
ret.add(item);
}
}
return ret;
}