code: def test_selectbox_interaction():
      """Test interactions with an empty selectbox widget."""
  
      def script():
          import streamlit as st
  
          st.selectbox("the label", ("m", "f"), index=None)
  
      at = AppTest.from_function(script).run()
      selectbox = at.selectbox[0]
      assert selectbox.value is None
  
      # Select option m
      at = selectbox.set_value("m").run()
      selectbox = at.selectbox[0]
      assert selectbox.value == "m"
  
      # # Clear the value
      at = selectbox.set_value(None).run()
      selectbox = at.selectbox[0]
      assert selectbox.value is None
  
imports: from unittest.mock import MagicMock, patch
  import numpy
  import pandas
  import pytest
  from parameterized import parameterized
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from streamlit.proto.LabelVisibilityMessage_pb2 import LabelVisibilityMessage
  from streamlit.testing.v1.app_test import AppTest
  from streamlit.testing.v1.util import patch_config_options
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 1 for calling a global function with example usage: test_selectbox_interaction() without return types