code: def _run_test(self, train_sf, test_sf, target="target"):
      for model in [
          tc.classifier.decision_tree_classifier,
          tc.classifier.random_forest_classifier,
          tc.classifier.boosted_trees_classifier,
      ]:
          m = model.create(train_sf, target=target, validation_set=None)
          for leaf in m.extract_features(test_sf)[-1]:
              self.assertTrue(leaf > 1e-5)
  
file_path: turicreate/src/python/turicreate/test/test_external_memory_tree.py
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import turicreate
  from array import array
  import pytest
label_desc: Use image node_id 1 for calling the TreeExtractFeaturesTest obj's underlying member method code with example usage: obj._run_test(train_sf, test_sf, target) without return types