What is the purpose of update?

[GoogleCodeExporter]

I start some action and wait until some file is deleted afterwards. I think 
that I have missed the expected file delete event. Might be it is because file 
was deleted before I call "update". I do not understand the purpose of 
"update". Can I use the file watcher not to miss any events? How do I kick off 
the process to remove the file and detect the event of effect?

Original issue reported on code.google.com by [email protected] on 21 Nov 2014 at 7:41