childManager property
The delegate that manages the children of this object.
Rather than having a concrete list of children, a RenderSliverVariableSizeBoxAdaptor uses a RenderSliverVariableSizeBoxChildManager to create children during layout in order to fill the SliverConstraints.remainingPaintExtent.
Implementation
@protected
RenderSliverVariableSizeBoxChildManager get childManager => _childManager;