class_docstr: Test `Wikilinks` Extension. 
class_docstr_tok: ["Test","`","Wikilinks","`","Extension","."]
docstr: Test used of a custom URL builder. 
docstr_tok: ["Test","used","of","a","custom","URL","builder","."]
code: def testURLCallback(self):
      """Test used of a custom URL builder."""
  
      from markdown.extensions.wikilinks import WikiLinkExtension
  
      def my_url_builder(label, base, end):
          return "/bar/"
  
      md = markdown.Markdown(
          extensions=[WikiLinkExtension(build_url=my_url_builder)]
      )
      self.assertEqual(
          md.convert("[[foo]]"),
          '<p><a class="wikilink" href="/bar/">foo</a></p>',
      )
  
imports: import unittest
  import markdown
label_desc: Use image node_id 7 for calling the TestWikiLinks obj's underlying member method code with example usage: obj.testURLCallback() and returns: str