code: def df():
      return pd.DataFrame(
          {
              "a": [1, 2, 3, 4, 5, 6],
              "b": np.log([10, 9, 8, 7, 6, 5]),
              "c": ["a", "b", "a", "b", "c", "c"],
              "d": ["b", "a", "a", "b", "a", "b"],
              "e": [0, 1, 0, 1, 0, 1],
          }
      )
  
file_path: scikit-lego/tests/test_preprocessing/test_formulaic_transformer.py
imports: import joblib
  import numpy
  import pandas
  import pytest
  from scipy.sparse import spmatrix
  from sklearn.linear_model import LogisticRegression
  from sklearn.pipeline import Pipeline
  from sklearn.preprocessing import StandardScaler
  from sklego.preprocessing import FormulaicTransformer
label_desc: Use image node_id 1 for calling a global function with example usage: df() and returns: pd