public void SetContents(VisualElement contents)
 {
     if (contents != null && contents != m_ContentContainer)
     {
         if (m_ContentContainer != null)
         {
             m_ContentContainer.RemoveFromHierarchy();
             m_ContentContainer.UnregisterCallback <GeometryChangedEvent>(OnGeometryChanged);
             m_ContentContainer.RemoveFromClassList(contentViewClass);
         }
         AssignContentContainer(contents);
         scrollOffset = Vector2.zero;
     }
 }