code: def test_predict_confidence_threshold(self):
      sf = self.test.head()
      pred = self.model.predict(sf.head(), confidence_threshold=1.0)
      stacked = tc.object_detector.util.stack_annotations(pred)
      # This should return no predictions, especially with an unconverged model
      self.assertEqual(len(stacked), 0)
  
      pred = self.model.predict(sf.head(), confidence_threshold=0.0)
      stacked = tc.object_detector.util.stack_annotations(pred)
      # This should return predictions
      self.assertTrue(len(stacked) > 0)
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import pytest
  from .None import util
  import turicreate
  import tempfile
  import numpy
  import platform
  import pytest
  import sys
  import os
  from turicreate.toolkits._main import ToolkitError
  from turicreate.toolkits._internal_utils import _raise_error_if_not_sarray, _mac_ver
label_desc: Use image node_id 12 for calling the OneObjectDetectorSmokeTest obj's underlying member method code with example usage: obj.test_predict_confidence_threshold() without return types