code: def test_catalog_info_for_sub_domain_file_and_path():
      cat = i18n.CatalogInfo("path", "sub/domain", "utf-8")
      assert cat.po_file == "sub/domain.po"
      assert cat.mo_file == "sub/domain.mo"
      assert cat.po_path == os.path.join("path", "sub/domain.po")
      assert cat.mo_path == os.path.join("path", "sub/domain.mo")
  
file_path: sphinx/tests/test_util/test_util_i18n.py
imports: import datetime
  import os
  import babel
  import pytest
  from babel.messages.mofile import read_mo
  from sphinx.errors import SphinxError
  from sphinx.util import i18n
label_desc: Use image node_id 2 for calling a global function with example usage: test_catalog_info_for_sub_domain_file_and_path() without return types