Remember loaded files in panes when switching layouts

For example I do this:
* Create a new window.
* Load 3 files into the pane.
* Switch to a 2 pane layout.
* Move one file into the other pane.
* Switch back to the 1 pane layout.
* Switch back to the 2 pane layout.

I wish that it would remember that I moved that file into the second pane before.