code: def _format_marker(
      marker: Union[List[str], Tuple[Node, ...], str],
      first: Optional[bool] = True,
  ) -> str:
      assert isinstance(marker, (list, tuple, str))
  
      # Sometimes we have a structure like [[...]] which is a single item list
      # where the single item is itself it's own list. In that case we want skip
      # the rest of this function so that we don't get extraneous () on the
      # outside.
      if (
          isinstance(marker, list)
          and len(marker) == 1
          and isinstance(marker[0], (list, tuple))
      ):
          return _format_marker(marker[0])
  
      if isinstance(marker, list):
          inner = (_format_marker(m, first=False) for m in marker)
          if first:
              return " ".join(inner)
          else:
              return "(" + " ".join(inner) + ")"
      elif isinstance(marker, tuple):
          return " ".join([m.serialize() for m in marker])
      else:
          return marker
  
imports: import operator
  import os
  import platform
  import sys
  from typing import Any, Callable, Dict, List, Optional, Tuple, Union
  from pyparsing import Forward, Group, Literal, ParseException, ParseResults, QuotedString, ZeroOrMore, stringEnd, stringStart
  from .specifiers import InvalidSpecifier, Specifier
label_desc: Use image node_id 2 for calling a global function with example usage: _format_marker(marker, first) and returns: _format_marker, str, unknown, str, marker