code: def test_tokenize_url(self):
      url = "http://www.google.com"
      tokens = ["http", "www", "google", "com"]
      self.assertEqual(tokens, cf_utils.tokenize_url(url))
  
      url = "http://www.gmail.com/mail/u/1/#inbox"
      tokens = [
          "http",
          "www",
          "gmail",
          "com",
          "mail",
          "u",
          "1",
          "inbox",
      ]
      self.assertEqual(tokens, cf_utils.tokenize_url(url))
  
      url = "foobar"
      tokens = ["foobar"]
      self.assertEqual(tokens, cf_utils.tokenize_url(url))
  
      url = ""
      self.assertEmpty(cf_utils.tokenize_url(url))
  
      url = "/"
      self.assertEmpty(cf_utils.tokenize_url(url))
  
      url = "//"
      self.assertEmpty(cf_utils.tokenize_url(url))
  
      url = "//foobar/"
      tokens = ["foobar"]
      self.assertEqual(tokens, cf_utils.tokenize_url(url))
  
imports: from absl.testing import absltest
  from lit_nlp.components import cf_utils
label_desc: Use image node_id 1 for calling the CfUtilsTest obj's underlying member method code with example usage: obj.test_tokenize_url() without return types