docs: def extract(list_name, base_url, list_config=None, user=None, password=None):
      '''
      # FIXME DOCS
      '''
      if not (base_url and list_name):
          raise RuntimeError(
              "base_url [{}] and list_name [{}] can not be NULL".format(
                  base_url, list_name))
  
      list_config = list_config or {}
      assert isinstance(list_config, dict)
  
      logr.debug(
          '[{}] {}: {}'.format(base_url, list_name, user))
  
      list_url = "{}/roster/{}".format(base_url, list_name)
  
      content = _download(list_url, user, password)
  
      # Check for and report any errors return in the HTML
      check_h2(content, 'Error')
  
      # source contain list members page content
      users = re.findall(r'(?<=>)(\S* at \S*|\S*@\S*)(?=<\/a>)', content)
      users = ['@'.join(u.split(' at ')) if ' at ' in u else u
               for u in users]
  
      return users