public LayoutModelBuilder deriveForStorage(final RenderBox clonedContent) {
   final DefaultLayoutModelBuilder clone = clone();
   clone.context = context.deriveForStorage(clonedContent);
   return clone;
 }
 public LayoutModelBuilder deriveForPageBreak() {
   final DefaultLayoutModelBuilder clone = clone();
   clone.context = context.deriveForPagebreak();
   return clone;
 }