code: def test_array_dtype(self):
      np.random.seed(42)
      sf = tc.SFrame()
      sf["arr"] = np.random.rand(100, 3)
      with tempfile.NamedTemporaryFile(
          mode="w", suffix=".json"
      ) as json_file:
          sf.save(json_file.name, format="json")
          with open(json_file.name) as json_data:
              # will throw if JSON export doesn't work
              loaded = json.load(json_data)
  
file_path: turicreate/src/python/turicreate/test/test_json_export.py
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import json
  import numpy
  import struct
  import tempfile
  import unittest
  import turicreate
  import pytest
label_desc: Use image node_id 2 for calling the JSONExporterTest obj's underlying member method code with example usage: obj.test_array_dtype() without return types