code: def test_transform_works_with_single_row_df(self):
      columns = ["column1", "column2", "column3", "column4"]
      df = pd.DataFrame(
          [[i, i, i, i] for i in range(10)], columns=columns
      )
      df = df.iloc[2:8, :]
      target_columns = ["column1", "column2", "column3"]
  
      multi_process_encoder = encoders.HashingEncoder(
          cols=target_columns
      )
      multi_process_encoder.fit(df, None)
      df_encoded_multi_process = multi_process_encoder.transform(
          df.sample(1)
      )
  
      assert (
          multi_process_encoder.n_components
          + len(list(set(columns) - set(target_columns)))
          == df_encoded_multi_process.shape[1]
      )
  
file_path: category_encoders/tests/test_hashing.py
imports: from unittest import TestCase
  import pandas
  from pandas.testing import assert_frame_equal, assert_index_equal
  import category_encoders
label_desc: Use image node_id 2 for calling the TestHashingEncoder obj's underlying member method code with example usage: obj.test_transform_works_with_single_row_df() without return types