class_docstr: tracker for rabit
class_docstr_tok: ["tracker","for","rabit"]
code: def get_tree(self, nslave):
      tree_map = {}
      parent_map = {}
      for r in range(nslave):
          tree_map[r] = self.get_neighbor(r, nslave)
          parent_map[r] = (r + 1) // 2 - 1
      return tree_map, parent_map
  
imports: from __future__ import absolute_import
  import os
  import sys
  import socket
  import struct
  import subprocess
  import argparse
  import time
  import logging
  from threading import Thread
label_desc: Use image node_id 5 for calling the RabitTracker obj's underlying member method code with example usage: obj.get_tree(nslave) and returns: tree_map,  parent_map