code: def _parse_marker_item(tokenizer: Tokenizer) -> MarkerItem:
      """
      marker_item = WS? marker_var WS? marker_op WS? marker_var WS?
      """
      tokenizer.consume("WS")
      marker_var_left = _parse_marker_var(tokenizer)
      tokenizer.consume("WS")
      marker_op = _parse_marker_op(tokenizer)
      tokenizer.consume("WS")
      marker_var_right = _parse_marker_var(tokenizer)
      tokenizer.consume("WS")
      return (marker_var_left, marker_op, marker_var_right)
  
imports: import ast
  from typing import Any, List, NamedTuple, Optional, Tuple, Union
  from ._tokenizer import DEFAULT_RULES, Tokenizer
label_desc: Use image node_id 12 for calling a global function with example usage: _parse_marker_item(tokenizer) and returns: marker_var_left,  marker_op,  marker_var_right