Yes. The `hideFrame` RPC call is what actually moves the sidebar offscreen. The `setActiveHighlights` call serves to remove any highlights being shown as a result of hovering. Maybe that is implicit now that it's only hover. It may be left over from when we had a "summary" and "detail" view that were separate, and the detail view locked the highlights on for the selected annotation.

I think it should stay, since if the host page calls annotator.hideFrame() I would want the temporary highlights to go away for sure rather than relying on the sidebar moving away to trigger a mouseleave event that causes the highlights to be removed.

I could try without it. I bet it would work. But it seems safer to leave it. What do you think?