def xen(self, base_tree, results_dir = '', tmp_dir = '', leave = False, \ kjob = None ): """Summon a xen object""" (results_dir, tmp_dir) = self.setup_dirs(results_dir, tmp_dir) build_dir = 'xen' return xen.xen(self, base_tree, results_dir, tmp_dir, build_dir, leave, kjob)