code: def test_fit_where_y_train_contains_unlabeled(self):
      train_set = random_transformer_dataset(10)
      train_set.y = np.array([LABEL_UNLABELED] * 10)
  
      model_args = TransformerModelArguments(
          "sshleifer/tiny-distilroberta-base"
      )
      classifier = TransformerBasedClassification(model_args, 2)
      with self.assertRaisesRegex(
          ValueError, "Training set labels must be labeled"
      ):
          classifier.fit(train_set)
  
imports: import unittest
  import pytest
  import numpy
  from unittest.mock import patch
  from small_text.base import LABEL_UNLABELED
  from small_text.integrations.pytorch.exceptions import PytorchNotFoundError
  from small_text.training.early_stopping import EarlyStopping, EarlyStoppingOrCondition
  from small_text.training.metrics import Metric
  from small_text.utils.logging import VERBOSITY_MORE_VERBOSE
label_desc: Use image node_id 3 for calling the TestTransformerBasedClassification obj's underlying member method code with example usage: obj.test_fit_where_y_train_contains_unlabeled() without return types