code: def get_header_as_text(file_content, reference_id):
      
      res = _CONTENT_PATTERN.findall(file_content)
      if len(res) == 2:
          content = res[0]
      elif len(res) == 1:
          return ''
      else:
          raise ValueError('Unexpected <code><pre> sections: "%r"' % res)
      return _clean_html(content)
docs: \
      Returns the cable's header as text.
      
      `file_content`
          The HTML file content, c.f. `get_file_content`.