code: def test_bidirectional(self):
      self.assertEqual(self.db.bidirectional("\uFFFE"), "")
      self.assertEqual(self.db.bidirectional(" "), "WS")
      self.assertEqual(self.db.bidirectional("A"), "L")
      self.assertEqual(self.db.bidirectional("\U00020000"), "L")
  
      self.assertRaises(TypeError, self.db.bidirectional)
      self.assertRaises(TypeError, self.db.bidirectional, "xx")
  
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 9 for calling the UnicodeFunctionsTest obj's underlying member method code with example usage: obj.test_bidirectional() without return types