code: def test_tab_base(fake_writer):
      bar = _create_bar()
      line = _create_line()
      tab = Tab().add(bar, "bar-example").add(line, "line-example")
      tab.render()
      _, content = fake_writer.call_args[0]
      assert_in("bar-example", content)
      assert_in("line-example", content)
  
imports: from typing import Iterable
  from unittest.mock import patch
  from nose.tools import assert_equal, assert_in, assert_true
  from pyecharts import options
  from pyecharts.charts import Bar, Line, Tab
  from pyecharts.commons.utils import OrderedSet
  from pyecharts.components import Table
  from pyecharts.faker import Faker
  from pyecharts.globals import ThemeType
label_desc: Use image node_id 4 for calling a global function with example usage: test_tab_base(fake_writer) without return types