code: def _parse_marker_op(tokenizer: Tokenizer) -> Op:
      """
      marker_op = IN | NOT IN | OP
      """
      if tokenizer.check("IN"):
          tokenizer.read()
          return Op("in")
      elif tokenizer.check("NOT"):
          tokenizer.read()
          tokenizer.expect("WS", expected="whitespace after 'not'")
          tokenizer.expect("IN", expected="'in' after 'not'")
          return Op("not in")
      elif tokenizer.check("OP"):
          return Op(tokenizer.read().text)
      else:
          return tokenizer.raise_syntax_error(
              "Expected marker operator, one of "
              "<=, <, !=, ==, >=, >, ~=, ===, in, not in"
          )
  
imports: import ast
  from typing import Any, List, NamedTuple, Optional, Tuple, Union
  from ._tokenizer import DEFAULT_RULES, Tokenizer
label_desc: Use image node_id 17 for calling a global function with example usage: _parse_marker_op(tokenizer) and returns: Op, Op, Op, tokenizer