class_docstr: Test ability to marshall selectbox protos.
docstr: Test that it formats options.
docstr_tok: ["Test","that","it","formats","options","."]
code: def test_format_function(self):
      """Test that it formats options."""
      arg_options = [
          {"name": "john", "height": 180},
          {"name": "lisa", "height": 200},
      ]
      proto_options = ["john", "lisa"]
  
      st.selectbox(
          "the label", arg_options, format_func=lambda x: x["name"]
      )
  
      c = self.get_delta_from_queue().new_element.selectbox
      self.assertEqual(c.label, "the label")
      self.assertEqual(c.default, 0)
      self.assertEqual(c.options, proto_options)
  
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 9 for calling the SelectboxTest obj's underlying member method code with example usage: obj.test_format_function() without return types