def use_dill( self ):
        """Make the cluster use Dill as pickler for transferring results. This isn't
        generally needed, but is sometimes useful for particularly complex experiments
        such as those involving closures. (Or, to put it another way, if you find yourself
        tempted to use this method, consider re-structuring your experiment code.)"""
        self.open()
        with self.sync_imports(quiet = True):
            import dill
        self._client.direct_view().use_dill()