code: import unittest
  from unittest.mock import MagicMock
  
  import pandas as pd
  from pandas.testing import assert_frame_equal
  
  from data_export.pipeline.dataset import Dataset
  
  
  class TestDataset(unittest.TestCase):
      def setUp(self):
          example = MagicMock()
          example.to_dict.return_value = {"data": "example"}
          self.examples = MagicMock()
          self.examples.__iter__.return_value = [example]
          label = MagicMock()
          label.find_by.return_value = {"labels": ["label"]}
          self.labels = MagicMock()
          self.labels.__iter__.return_value = [label]
  
      def test_to_dataframe(self):
          dataset = Dataset(self.examples, self.labels)
          df = dataset.to_dataframe()
          expected = pd.DataFrame([{"data": "example", "labels": ["label"]}])
          assert_frame_equal(df, expected)
  
apis: pandas.DataFrame pandas.testing.assert_frame_equal