code: def _validate_flavor(flavor):
      if flavor is None:
          flavor = "lxml", "bs4"
      elif isinstance(flavor, str):
          flavor = (flavor,)
      elif isinstance(flavor, abc.Iterable):
          if not all(isinstance(flav, str) for flav in flavor):
              raise TypeError(
                  f"Object of type {repr(type(flavor).__name__)} "
                  f"is not an iterable of strings"
              )
      else:
          msg = repr(flavor) if isinstance(flavor, str) else str(flavor)
          msg += " is not a valid flavor"
          raise ValueError(msg)
  
      flavor = tuple(flavor)
      valid_flavors = set(_valid_parsers)
      flavor_set = set(flavor)
  
      if not flavor_set & valid_flavors:
          raise ValueError(
              f"{_print_as_set(flavor_set)} is not a valid set of flavors, valid "
              f"flavors are {_print_as_set(valid_flavors)}"
          )
      return flavor
  
imports: from __future__ import annotations
  from collections import abc
  import numbers
  import re
  from typing import TYPE_CHECKING, Iterable, Literal, Pattern, Sequence, cast
  from pandas._libs import lib
  from pandas._typing import BaseBuffer, DtypeBackend, FilePath, ReadBuffer
  from pandas.compat._optional import import_optional_dependency
  from pandas.errors import AbstractMethodError, EmptyDataError
  from pandas.util._validators import check_dtype_backend
  from pandas.core.dtypes.common import is_list_like
  from pandas import isna
  from pandas.core.indexes.base import Index
  from pandas.core.indexes.multi import MultiIndex
  from pandas.core.series import Series
  from pandas.io.common import file_exists, get_handle, is_url, stringify_path, urlopen, validate_header_arg
  from pandas.io.formats.printing import pprint_thing
  from pandas.io.parsers import TextParser
label_desc: Use image node_id 10 for calling a global function with example usage: _validate_flavor(flavor) and returns: flavor