docs: def if_pandas_df_convert_to_numpy(obj):
      """Return a Numpy array from a Pandas dataframe.
  
      Iterating over a DataFrame has weird side effects, such as the first
      row being the column names. Converting to Numpy is more safe.
      """
      if pd is not None and isinstance(obj, pd.DataFrame):
          return obj.values
      else:
          return obj