code: def test_add_default_except_tags() -> None:
      assert set(_add_default_except_tags("tag1,tag2").split(",")) == {
          "tag1",
          "tag2",
          "manual",
      }
      assert _add_default_except_tags("") == "manual"
      assert _add_default_except_tags("manual") == "manual"
  
file_path: ray/ci/ray_ci/test_tester.py
imports: import os
  import re
  import sys
  from tempfile import TemporaryDirectory
  from unittest import mock
  import pytest
  from ci.ray_ci.linux_tester_container import LinuxTesterContainer
  from ci.ray_ci.windows_tester_container import WindowsTesterContainer
  from ci.ray_ci.tester import _add_default_except_tags, _get_container, _get_all_test_query, _get_test_targets, _get_flaky_test_targets, _get_tag_matcher
label_desc: Use image node_id 4 for calling a global function with example usage: test_add_default_except_tags() without return types