code: def test_sfa_anova(binning_method):
      """Test SFA expected breakpoints."""
      # load training data
      X, y = load_gunpoint(split="train", return_X_y=True)
  
      word_length = 6
      alphabet_size = 4
  
      # SFA with ANOVA one-sided test
      window_size = 32
      p = SFA(
          word_length=word_length,
          anova=True,
          alphabet_size=alphabet_size,
          window_size=window_size,
          binning_method=binning_method,
      ).fit(X, y)
  
      assert p.breakpoints.shape == (word_length, alphabet_size)
      _ = p.transform(X, y)
  
      # SFA with first feq coefficients
      p2 = SFA(
          word_length=word_length,
          anova=False,
          alphabet_size=alphabet_size,
          window_size=window_size,
          binning_method=binning_method,
      ).fit(X, y)
  
      assert p.dft_length != p2.dft_length
      assert (p.breakpoints != p2.breakpoints).any()
      _ = p2.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 3 for calling a global function with example usage: test_sfa_anova(binning_method) without return types