code: def test_stop_with_predictions_none(self):
      stopping_criterion = DeltaFScore(2)
  
      with self.assertRaises(ValueError):
          stopping_criterion.stop()
  
      with self.assertRaises(ValueError):
          stopping_criterion.stop(
              predictions=np.array([None, None, None])
          )
  
file_path: small-text/tests/unit/small_text/stopping_criteria/test_base.py
imports: import unittest
  import numpy
  from numpy.testing import assert_array_equal, assert_array_almost_equal
  from small_text.stopping_criteria.base import DeltaFScore
label_desc: Use image node_id 7 for calling the DeltaFScoreTest obj's underlying member method code with example usage: obj.test_stop_with_predictions_none() without return types