code: def load_turicreate_json_tree(cls, jstree):
      vertices = jstree["vertices"]
      edges = jstree["edges"]
      vtup = map(lambda x: (x["id"], GBDTNode.load_vertex(x)), vertices)
      id2ver = dict(vtup)
      for e in edges:
          src = id2ver[e["src"]]
          dst = id2ver[e["dst"]]
          val = e["value"]
          if val == "yes":
              src.left = dst
          else:
              src.right = dst
      r = id2ver[0]  # root node
      return r
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import turicreate
  import unittest
  import json
  import random
  import numpy
  import pytest
label_desc: Use image node_id 3 for calling the GBDTNode obj's underlying member method code with example usage: obj.load_turicreate_json_tree(cls, jstree) and returns: r