code: def iter_subschema(
      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}"
  
      return iter_schema(child, path, ctx)
  
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 15 for calling a global function with example usage: iter_subschema(schema, path, key, ctx) and returns: iter_schema, list