class_docstr: A lightweight wrapper of a dict that sends forwardMsgs when state changes.
  It stores str keys with str and List[str] values.
class_docstr_tok: ["A","lightweight","wrapper","of","a","dict","that","sends","forwardMsgs","when","state","changes",".","It","stores","str","keys","with","str","and","List","[","str","]","values","."]
code: def __iter__(self) -> Iterator[str]:
      self._ensure_single_query_api_used()
  
      return iter(
          key
          for key in self._query_params.keys()
          if key not in EMBED_QUERY_PARAMS_KEYS
      )
  
imports: from dataclasses import dataclass, field
  from typing import Dict, Iterable, Iterator, List, MutableMapping, Union
  from urllib import parse
  from streamlit.constants import EMBED_QUERY_PARAMS_KEYS
  from streamlit.errors import StreamlitAPIException
  from streamlit.proto.ForwardMsg_pb2 import ForwardMsg
label_desc: Use image node_id 1 for calling the QueryParams obj's underlying member method code with example usage: obj.__iter__() and returns: iter