code: def test_fit_transform_int_idx_output(df_int_idx):
      """Tests that we get the expected outputs."""
      transformer = TimeSince(
          start=None,
          to_numeric=True,
          keep_original_columns=False,
          positive_only=False,
      )
  
      Xt = transformer.fit_transform(df_int_idx)
  
      expected = pd.DataFrame(
          data={"time_since_1": [0, 1, 2, 4, 8]}, index=df_int_idx.index
      )
      assert_frame_equal(Xt, expected)
  
imports: import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  from sktime.transformations.series.time_since import TimeSince
  from sktime.utils._testing.hierarchical import _make_hierarchical
label_desc: Use image node_id 7 for calling a global function with example usage: test_fit_transform_int_idx_output(df_int_idx) without return types