code: def iter_subdict(
      schema: dict, path: str, key: str, ctx: LintContext
  ) -> Errors:
      """Helper function to iter_schema()."""
  
      if key not in schema:
          return []
  
      child = schema[key]
      path += f".{key}"
  
      if not isinstance(child, dict):
          return [
              (path, "expected a dict but got a {type(child).__name__}")
          ]
  
      errors = []
  
      for key, sub in child.items():
          errors += iter_schema(sub, path + f".{key}", ctx)
  
      return errors
  
imports: import argparse
  import json
  import os
  import re
  import sys
  from typing import Callable, List, Optional, Tuple, TypeVar, Union
label_desc: Use image node_id 13 for calling a global function with example usage: iter_subdict(schema, path, key, ctx) and returns: errors, list, list