class_docstr: Test UserInfoProxy.
class_docstr_tok: ["Test","UserInfoProxy","."]
docstr: Test that an error is raised when called non existed attr.
docstr_tok: ["Test","that","an","error","is","raised","when","called","non","existed","attr","."]
code: def test_user_non_existing_attr(self):
      """Test that an error is raised when called non existed attr."""
      with self.assertRaises(AttributeError):
          st.write(st.experimental_user.attribute)
  
file_path: streamlit/lib/tests/streamlit/user_info_test.py
imports: import threading
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from streamlit.runtime.forward_msg_queue import ForwardMsgQueue
  from streamlit.runtime.scriptrunner import ScriptRunContext, add_script_run_ctx, get_script_run_ctx
  from streamlit.runtime.state import SafeSessionState, SessionState
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 3 for calling the UserInfoProxyTest obj's underlying member method code with example usage: obj.test_user_non_existing_attr() without return types