code: def test_bit_size():
      """Test expected bit size on training data."""
      # load training data
      X, y = load_gunpoint(split="train", return_X_y=True)
  
      word_length = 40
      alphabet_size = 12
      window_size = 75
  
      p = SFA(
          word_length=word_length,
          alphabet_size=alphabet_size,
          levels=2,
          bigrams=True,
          window_size=window_size,
      ).fit(X, y)
  
      w = p.transform(X)
      lengths = [x.bit_length() for x in list(w[0][0].keys())]
  
      assert np.min(lengths) > 128
      assert len(p.word_list(list(w[0][0].keys())[0])[0]) == 40
  
file_path: sktime/sktime/transformations/panel/dictionary_based/tests/test_sfa.py
imports: import sys
  import numpy
  import pytest
  from sktime.datasets import load_gunpoint
  from sktime.datatypes._panel._convert import from_nested_to_2d_array
  from sktime.tests.test_switch import run_test_for_class
  from sktime.transformations.panel.dictionary_based._sfa import SFA
label_desc: Use image node_id 5 for calling a global function with example usage: test_bit_size() without return types