code: def test_word_lengths(
      word_length,
      alphabet_size,
      window_size,
      bigrams,
      levels,
      use_fallback_dft,
  ):
      """Test expected word lengths."""
      # load training data
      X, y = load_gunpoint(split="train", return_X_y=True)
  
      p = SFA(
          word_length=word_length,
          alphabet_size=alphabet_size,
          window_size=window_size,
          bigrams=bigrams,
          levels=levels,
          use_fallback_dft=use_fallback_dft,
      ).fit(X, y)
  
      assert p.breakpoints is not None
      _ = p.transform(X, y)
  
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 4 for calling a global function with example usage: test_word_lengths(word_length, alphabet_size, window_size, bigrams, levels, use_fallback_dft) without return types