code: def normalize_mark_list(mark_list):
      """
      normalizes marker decorating helpers to mark objects
  
      :type mark_list: List[Union[Mark, Markdecorator]]
      :rtype: List[Mark]
      """
      extracted = [
          getattr(mark, "mark", mark) for mark in mark_list
      ]  # unpack MarkDecorator
      for mark in extracted:
          if not isinstance(mark, Mark):
              raise TypeError("got {!r} instead of Mark".format(mark))
      return [x for x in extracted if isinstance(x, Mark)]
  
imports: import inspect
  import warnings
  from collections import namedtuple
  from operator import attrgetter
  import attr
  import six
  from ..compat import ascii_escaped
  from ..compat import ATTRS_EQ_FIELD
  from ..compat import getfslineno
  from ..compat import MappingMixin
  from ..compat import NOTSET
  from _pytest.deprecated import PYTEST_PARAM_UNKNOWN_KWARGS
  from _pytest.outcomes import fail
  from _pytest.warning_types import PytestUnknownMarkWarning
label_desc: Use image node_id 5 for calling a global function with example usage: normalize_mark_list(mark_list) and returns: unknown