code: def test_ew_empty_series(method):
      vals = Series([], dtype=np.float64)
  
      ewm = vals.ewm(3)
      result = getattr(ewm, method)()
      tm.assert_almost_equal(result, vals)
  
imports: import numpy
  import pytest
  from pandas import DataFrame, DatetimeIndex, Series, date_range
  import pandas._testing
label_desc: Use image node_id 23 for calling a global function with example usage: test_ew_empty_series(method) without return types