On the move into public, its abstract methods columnVisibility/Width/Propertychanged scope from protected to package - this makes the base class rather useless
for extension: it's main job is sync'ing the cell's visible property to the column's visible property and triggering and doing the cell's layout. Both are possible only, if subclasses provide the column properties.
Would suggest to change scope back to protected. Or any special reasons for not doing it? Cheers Jeanette
