code: def _sync_nodes(self, ctx: Context):
      nodes = ctx.guest.get("sync_nodes")
      cur_layer_nodes, next_layer_nodes = nodes
      return cur_layer_nodes, next_layer_nodes
  
imports: from fate.ml.ensemble.learner.decision_tree.tree_core.decision_tree import DecisionTree, Node, _update_sample_pos_on_local_nodes, FeatureImportance
  from fate.ml.ensemble.learner.decision_tree.tree_core.hist import SBTHistogramBuilder, DistributedHistogram
  from fate.ml.ensemble.learner.decision_tree.tree_core.splitter import SBTSplitter
  from fate.ml.ensemble.learner.decision_tree.tree_core.decision_tree import ALL_FEAT, GUEST_FEAT_ONLY
  from fate.arch import Context
  from fate.arch.dataframe import DataFrame
  from typing import List
  import functools
  import logging
label_desc: Use image node_id 6 for calling the HeteroDecisionTreeHost obj's underlying member method code with example usage: obj._sync_nodes(ctx) and returns: cur_layer_nodes,  next_layer_nodes