docstr: Demangling a mangle parent directly should currently return an empty string.
docstr_tok: ["Demangling","a","mangle","parent","directly","should","currently","return","an","empty","string","."]
code: def test_demangle_base(self):
      """
      Demangling a mangle parent directly should currently return an empty string.
      """
      a = PackageMangler()
      mangled = a.mangle("foo")
      mangle_parent = mangled.partition(".")[0]
      self.assertEqual("", demangle(mangle_parent))
  
file_path: pytorch/test/package/test_mangling.py
imports: from io import BytesIO
  from torch.package import PackageExporter, PackageImporter
  from torch.package._mangling import demangle, get_mangle_prefix, is_mangled, PackageMangler
  from torch.testing._internal.common_utils import run_tests
label_desc: Use image node_id 7 for calling the TestMangling obj's underlying member method code with example usage: obj.test_demangle_base() without return types