code: def test_fit_transform_behaviour():
      """Tests that the transform method evaluates time steps passed based on X in fit."""
      transformer = FourierFeatures(
          sp_list=[12],
          fourier_terms_list=[2],
          keep_original_columns=True,
      )
      # fit_transform on one part of the dataset
      y_tr_1 = transformer.fit_transform(Y.iloc[:100])
      # transform the rest
      y_tr_2 = transformer.transform(Y.iloc[100:])
      # fit_transform the entire dataset
      y_tr_complete = transformer.fit_transform(Y)
      assert_frame_equal(pd.concat([y_tr_1, y_tr_2]), y_tr_complete)
  
file_path: sktime/sktime/transformations/series/tests/test_fourier.py
imports: from copy import deepcopy
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal, assert_index_equal
  from sktime.datasets import load_airline
  from sktime.transformations.series.fourier import FourierFeatures
label_desc: Use image node_id 7 for calling a global function with example usage: test_fit_transform_behaviour() without return types