code: def df_enc_binary():
      df = {
          "var_A": ["A"] * 6 + ["B"] * 10 + ["C"] * 4,
          "var_B": ["A"] * 10 + ["B"] * 6 + ["C"] * 4,
          "var_C": ["AHA"] * 12 + ["UHU"] * 8,
          "var_D": ["OHO"] * 5 + ["EHE"] * 15,
          "var_num": [
              1,
              1,
              0,
              0,
              0,
              0,
              0,
              0,
              0,
              0,
              1,
              1,
              0,
              0,
              0,
              0,
              1,
              1,
              0,
              0,
          ],
      }
      df = pd.DataFrame(df)
  
      return df
  
file_path: feature_engine/tests/test_encoding/test_onehot_encoder.py
imports: import pandas
  import pytest
  from sklearn.pipeline import Pipeline
  from feature_engine.encoding import OneHotEncoder
label_desc: Use image node_id 9 for calling a global function with example usage: df_enc_binary() and returns: df