class_docstr: Test abbr extension. 
class_docstr_tok: ["Test","abbr","extension","."]
docstr: Test Nested Abbreviations. 
docstr_tok: ["Test","Nested","Abbreviations","."]
code: def testNestedAbbr(self):
      """Test Nested Abbreviations."""
      text = "[ABBR](/foo) and _ABBR_\n\n" + "*[ABBR]: Abbreviation"
      self.assertEqual(
          self.md.convert(text),
          '<p><a href="/foo"><abbr title="Abbreviation">ABBR</abbr></a> '
          'and <em><abbr title="Abbreviation">ABBR</abbr></em></p>',
      )
  
imports: import unittest
  import markdown
label_desc: Use image node_id 3 for calling the TestAbbr obj's underlying member method code with example usage: obj.testNestedAbbr() without return types