I've pondered how one could set up conditions in documentation. For example display [collapsed] code in the document that implements the functionality there des

I've pondered how one could set up conditions in documentation. For example display [collapsed] code in the document that implements the functionality there described. If the exact code is no longer found in the source the article or section gets a warning banner, a [collapsed] div view and the wiki bug tracker displaying the issue. Perhaps one could also programmatically generate a list of missing articles by looking at code and implementations.