code: def test_df():
      return pd.DataFrame(
          {"X1": [0, 1, 2], "X2": [np.nan, "178", "154"]}
      )
  
imports: import logging
  import numpy
  import pandas
  import pytest
  from sklego.pandas_utils import _add_lagged_numpy_columns, _add_lagged_pandas_columns, add_lags, log_step, log_step_extra
label_desc: Use image node_id 1 for calling a global function with example usage: test_df() and returns: pd