docs: def _parse_single(self, text, tagname):
          """
          A hack to get the content of the XML responses from the CAS server.
  
          ## Arguments
  
          * `text` (str): The XML string to parse.
          * `tagname` (str): The tag that contains the info that we want.
  
          ## Returns
  
          * `content` (str): The contents of the tag.
  
          """
          return minidom.parseString(text)\
                  .getElementsByTagName(tagname)[0].firstChild.data