code: def test_lookup_nonexistant(self):
      # just make sure that lookup can fail
      for nonexistant in [
          "LATIN SMLL LETR A",
          "OPEN HANDS SIGHS",
          "DREGS",
          "HANDBUG",
          "MODIFIER LETTER CYRILLIC SMALL QUESTION MARK",
          "???",
      ]:
          self.assertRaises(KeyError, self.db.lookup, nonexistant)
  
imports: import hashlib
  from http.client import HTTPException
  import sys
  import unicodedata
  import unittest
  from test.support import open_urlresource, requires_resource, script_helper, cpython_only, check_disallow_instantiation
label_desc: Use image node_id 4 for calling the UnicodeFunctionsTest obj's underlying member method code with example usage: obj.test_lookup_nonexistant() without return types