RenderSliverOverlapAbsorber constructor
Create a sliver that absorbs overlap and reports it to a SliverOverlapAbsorberHandle.
The handle must not be null.
The child must be a RenderSliver.
Implementation
RenderSliverOverlapAbsorber({
@required SliverOverlapAbsorberHandle handle,
RenderSliver child,
}) : assert(handle != null), _handle = handle {
this.child = child;
}