code: def test_expanding_apply_empty_series(engine_and_raw):
      engine, raw = engine_and_raw
      ser = Series([], dtype=np.float64)
      tm.assert_series_equal(
          ser,
          ser.expanding().apply(
              lambda x: x.mean(), raw=raw, engine=engine
          ),
      )
  
imports: import numpy
  import pytest
  from pandas import DataFrame, DatetimeIndex, Index, MultiIndex, Series, isna, notna
  import pandas._testing
label_desc: Use image node_id 28 for calling a global function with example usage: test_expanding_apply_empty_series(engine_and_raw) without return types