https://sourceforge.net/tracker/?func=detail&aid=2985682&group_id=152762&atid=785194

An option is to monitor if label or property files are changed.
Issues: it costs too much resource (since a monitoring thread might be required, and there are a lot of files to monitor)

Alternatively, it might be done by application's invocation. In other words, it is invoked by the application explicitly when it is required.