class_docstr: Test the markdown.extensions.codehilite.CodeHilite class. 
class_docstr_tok: ["Test","the","markdown.extensions.codehilite.CodeHilite","class","."]
code: def test_codehilite_set_css_class(self):
      if has_pygments:
          expected = (
              '<div class="override"><pre><span></span><code>plain text\n'
              "</code></pre></div>"
          )
      else:
          expected = (
              '<pre class="override"><code class="language-text">plain text\n'
              "</code></pre>"
          )
      self.assertOutputEquals(
          "plain text", expected, lang="text", css_class="override"
      )
  
imports: from markdown.test_tools import TestCase
  from markdown.extensions.codehilite import CodeHiliteExtension, CodeHilite
  from markdown import extensions, treeprocessors
  import os
  import xml.etree.ElementTree
label_desc: Use image node_id 18 for calling the TestCodeHiliteClass obj's underlying member method code with example usage: obj.test_codehilite_set_css_class() without return types