docstr: Return a saved state value, None if item is undefined.
docstr_tok: ["Return","a","saved","state","value",",","None","if","item","is","undefined","."]
code: def __getitem__(self, item):
      """Return a saved state value, None if item is undefined."""
      return self._state["data"].get(item, None)
  
file_path: promptsource/promptsource/session.py
imports: from streamlit.hashing import _CodeHasher
  from streamlit.report_thread import get_report_ctx
  from streamlit.server.server import Server
label_desc: Use image node_id 3 for calling the _SessionState obj's underlying member method code with example usage: obj.__getitem__(item) and returns: self