Is it possible to add a custom flag to ViewSettings/ProjectViewSettings? I'd like to allow my plugin's users to toggle visibility for a subset of project files (XML metadata files that are generally just noise). I can do this now in my custom project tree structure provider, but I'm trying to figure out the best way to determine whether to do so. Right now I'm doing it based on ProjectViewSettings.isShowExcludedFiles(), but that's not really what I want because these aren't really excluded files in the same sense. I can obviously add my own flag that's configured elsewhere, but in a perfect world it just seems like it would be another checkbox in the project view settings drop-down. Can this be done?