Calls the argument for each child considered onstage.
Being onstage affects the element's discoverability during testing when you use Flutter's Finder objects. For example, when you instruct the test framework to tap on a widget, by default the finder will look for onstage elements and ignore the offstage ones.
The default implementation defers to visitChildren and therefore treats the element as onstage.
void debugVisitOnstageChildren(ElementVisitor visitor) => visitChildren(visitor);