code: def test_single_metric(self):
      for m in self.metrics:
          self._run_test(self.train, self.test, 5, m)
  
file_path: turicreate/src/python/turicreate/test/test_boosted_trees_early_stop.py
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import turicreate
  from turicreate.toolkits._main import ToolkitError
  import random
label_desc: Use image node_id 5 for calling the BoostedTreesRegressionEarlyStopTest obj's underlying member method code with example usage: obj.test_single_metric() without return types