Thread:Extension talk:CodeEditor/How to set the content of the textbox?

If I go to https://en.wikipedia.org/wiki/Special:MyPage/common.js?action=edit and type  in the console:
 * The code is replaced by "NEWCODE" if CodeEditor is disabled
 * Nothing happens if CodeEditor is enabled

What should be used to set the content of the textbox if CodeEditor is enabled? I know from en:Special:Diff/617061684 that we can get the contents by using But I have no idea what to use to set the content...
 * or