scrollBehavior property Null safety
A ScrollBehavior that will be applied to this widget individually.
The ScrollBehavior of the inherited ScrollConfiguration will be modified by default to not apply a Scrollbar. This is because the NestedScrollView cannot assume the configuration of the outer and inner Scrollable widgets, particularly whether to treat them as one scrollable, or separate and desirous of unique behaviors.
final ScrollBehavior? scrollBehavior;