docs: def document(self):
          """Render the error document"""
          resp = request.environ.get('pylons.original_response')
          page = error_document_template % \
              dict(prefix=request.environ.get('SCRIPT_NAME', ''),
                   code=request.params.get('code', resp.status_int),
                   message=request.params.get('message', resp.body))
          return page