code: def test_drifts():
      """Test drifts method of Drift_thresholder class."""
      drift_thresholder = Drift_thresholder()
      with pytest.raises(ValueError):
          drift_thresholder.drifts()
      reader = Reader(sep=",")
      dict = reader.train_test_split(
          Lpath=["data_for_tests/train.csv", "data_for_tests/test.csv"],
          target_name="Survived",
      )
      drift_thresholder.fit_transform(dict)
      drifts = drift_thresholder.drifts()
      assert drifts != {}
  
imports: import pytest
  from mlbox.preprocessing.drift_thresholder import Drift_thresholder
  from mlbox.preprocessing.reader import Reader
label_desc: Use image node_id 3 for calling a global function with example usage: test_drifts() without return types