Difficult to bring back code buffer pane

[xiaotian]

I use dap-ui's standard layout :

left stack is watch/stack/bp/scope
bottom is console and the control ui(icon/buttons).
remaining (top right) is my source buffer pane.

This works reasonably well, but if I accidentally close the source buf, then I am in a very bad situation and can't bring back the code buf pane easily. I have to jump through the following hoops:

1. switch focus to that icon/control plan at bottom left. (this is the only pane that allow me to open my source buf as a split :( )
2. :split # - this open my buf as a split on top of the icon/control pane, at this point, the code pane is back but the layout is all messed up.
3. require("dapui").toggle({ reset = true }) this will close all dapui panes
4. require("dapui").toggle({ reset = true }) this will bring back the console pane at right position. note you cannot just do 3 and 4, otherwise you end up with an additional watch pane at the code pane position.

I have tried many different ways(use stack frame, neotree, :e command, etc), none worked except this one, mostly because once the source buf pane is closed, there is no pane on which a buffer can be opened.

There should be an easier way to restore the layout, or bring back the code buffer pane.
Any easy way or magic I can bring back the source buffer pane? I am losing my sanity over this...

Thanks!