docstr: Test reference id whitespace cleanup.
code: def test_reference_newlines(self):
      """Test reference id whitespace cleanup."""
  
      self.assertMarkdownRenders(
          self.dedent(
              """
                  Two things:
  
                   - I would like to tell you about the [code of
                     conduct][] we are using in this project.
                   - Only one in fact.
  
                  [code of conduct]: https://github.com/Python-Markdown/markdown/blob/master/CODE_OF_CONDUCT.md
                  """
          ),
          "<p>Two things:</p>\n<ul>\n<li>I would like to tell you about the "
          '<a href="https://github.com/Python-Markdown/markdown/blob/master/CODE_OF_CONDUCT.md">code of\n'
          "   conduct</a> we are using in this project.</li>\n<li>Only one in fact.</li>\n</ul>",
      )
  
imports: from markdown.test_tools import TestCase
label_desc: Use image node_id 15 for calling the TestReferenceLinks obj's underlying member method code with example usage: obj.test_reference_newlines() without return types