code: def configure(self):
          
          lm = self.last_manifest
          for tracker in self.get_trackers():
              self.vprint('Checking tracker:', tracker)
              last_thumbprint = lm['_tracker_%s' % tracker.get_natural_key_hash()]
              self.vprint('last thumbprint:', last_thumbprint)
              has_changed = tracker.is_changed(last_thumbprint)
              self.vprint('Tracker changed:', has_changed)
              if has_changed:
                  self.vprint('Change detected!')
                  tracker.act()
docs: The standard method called to apply functionality when the manifest changes.