code: def test_digit(self):
      self.assertEqual(self.db.digit("A", None), None)
      self.assertEqual(self.db.digit("9"), 9)
      self.assertEqual(self.db.digit("\u215b", None), None)
      self.assertEqual(self.db.digit("\u2468"), 9)
      self.assertEqual(self.db.digit("\U00020000", None), None)
      self.assertEqual(self.db.digit("\U0001D7FD"), 7)
  
      self.assertRaises(TypeError, self.db.digit)
      self.assertRaises(TypeError, self.db.digit, "xx")
      self.assertRaises(ValueError, self.db.digit, "x")
  
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 5 for calling the UnicodeFunctionsTest obj's underlying member method code with example usage: obj.test_digit() without return types