code: def _header_line(self):
      # Store line for reuse in _get_index_name
      if self.header is not None:
          return None
  
      try:
          line = self._buffered_line()
      except StopIteration as err:
          if not self.names:
              raise EmptyDataError(
                  "No columns to parse from file"
              ) from err
  
          line = self.names[:]
      return line
  
imports: from __future__ import annotations
  from collections import abc, defaultdict
  import csv
  from io import StringIO
  import re
  from typing import IO, TYPE_CHECKING, DefaultDict, Literal, cast
  import warnings
  import numpy
  from pandas._libs import lib
  from pandas.errors import EmptyDataError, ParserError, ParserWarning
  from pandas.util._decorators import cache_readonly
  from pandas.util._exceptions import find_stack_level
  from pandas.core.dtypes.common import is_bool_dtype, is_integer, is_numeric_dtype
  from pandas.core.dtypes.inference import is_dict_like
  from pandas.io.common import dedup_names, is_potential_multi_index
  from pandas.io.parsers.base_parser import ParserBase, parser_defaults
label_desc: Use image node_id 10 for calling the PythonParser obj's underlying member method code with example usage: obj._header_line() and returns: line, None