'Unregister files handled by these functions.
:param set removed_functions:
Set of functions previously passed to ``.register()`` method.'

def unregister_functions(self, removed_functions):

    with self.lock:
        for (path, functions) in list(self.watched.items()):
            functions -= removed_functions
            if (not functions):
                self.watched.pop(path)
                self.loaded.pop(path, None)
