class_docstr: Internal class for formatting output data in html for display in Jupyter
  Notebooks. This class is intended for functionality specific to
  DataFrame._repr_html_() and DataFrame.to_html(notebook=True)
code: def _get_columns_formatted_values(self) -> list[str]:
      return self.columns.format()
  
imports: from __future__ import annotations
  from textwrap import dedent
  from typing import Any, Final, Hashable, Iterable, Mapping, cast
  from pandas._config import get_option
  from pandas._libs import lib
  from pandas import MultiIndex, option_context
  from pandas.io.common import is_url
  from pandas.io.formats.format import DataFrameFormatter, get_level_lengths
  from pandas.io.formats.printing import pprint_thing
label_desc: Use image node_id 2 for calling the NotebookFormatter obj's underlying member method code with example usage: obj._get_columns_formatted_values() and returns: self