BulkFileListener: check if VFileEvent describe changes from "outside" or from Idea

How to do subj?

I.e. how to distinguish if BulkFileListener#after()/before() fired because of file been changed from "outside" (let say due to git checkout command) or due to Idea doing saving changes made inside Idea on disk?

PS Both VFileEvent#isFromRefresh and VFileEvent#isFromSave seems to be useless in that case, or I'm wrong?...