code: def test_list_str():
      values = ["hello", "there", "guy"]
      first = values[0]
      c = interactive(f, lis=values)
      assert len(c.children) == 2
      d = dict(
          cls=widgets.Dropdown,
          value=first,
          options=tuple(values),
          _options_labels=tuple(values),
          _options_values=tuple(values),
      )
      check_widget_children(c, lis=d)
  
imports: from unittest.mock import patch
  import os
  from collections import OrderedDict
  import pytest
  import ipywidgets
  from traitlets import TraitError, Float
  from ipywidgets import interact, interact_manual, interactive, interaction, Output, Widget
  from .utils import setup, teardown
label_desc: Use image node_id 10 for calling a global function with example usage: test_list_str() without return types