code: def is_single_string_selector(
      selector: SelectorType, field: str
  ) -> bool:
      """Whether a selector is a simple single field, e.g. ``{name: "foo"}``
  
      Args:
          selector (JSON-like) : query selector
          field (str) : field name to check for
  
      Returns
          bool
  
      """
      return (
          len(selector) == 1
          and field in selector
          and isinstance(selector[field], str)
      )
  
imports: from __future__ import annotations
  import logging
  from typing import TYPE_CHECKING, Any, Callable, Iterable, Union
  from ..model import Model
label_desc: Use image node_id 2 for calling a global function with example usage: is_single_string_selector(selector, field) and returns: unknown