code: def test_should_not_get_slots_when_not_fitted(self):
      # Given
      slot_filler = CRFSlotFiller()
  
      # When / Then
      self.assertFalse(slot_filler.fitted)
      with self.assertRaises(NotTrained):
          slot_filler.get_slots("foobar")
  
imports: from __future__ import unicode_literals
  import io
  import os
  from builtins import range
  from pathlib import Path
  from unittest import skipIf
  from mock import MagicMock, PropertyMock
  from sklearn_crfsuite import CRF
  from snips_nlu.constants import DATA, END, ENTITY, LANGUAGE_EN, SLOT_NAME, START, TEXT, RANDOM_STATE
  from snips_nlu.dataset import Dataset
  from snips_nlu.entity_parser import CustomEntityParserUsage
  from snips_nlu.exceptions import NotTrained
  from snips_nlu.pipeline.configs import CRFSlotFillerConfig
  from snips_nlu.preprocessing import tokenize, Token
  from snips_nlu.result import unresolved_slot
  from snips_nlu.slot_filler.crf_slot_filler import CRFSlotFiller, _ensure_safe, _encode_tag, CRF_MODEL_FILENAME
  from snips_nlu.slot_filler.crf_utils import TaggingScheme
  from snips_nlu.slot_filler.feature_factory import IsDigitFactory, NgramFactory, ShapeNgramFactory
  from snips_nlu.tests.utils import FixtureTest, TEST_PATH
label_desc: Use image node_id 7 for calling the TestCRFSlotFiller obj's underlying member method code with example usage: obj.test_should_not_get_slots_when_not_fitted() without return types