code: def _get_validated_visibility_timeout(self, timeout=None):
          
          if timeout is not None:
              visibility_timeout = int(timeout)
          else:
              visibility_timeout = int(self.querystring.get("VisibilityTimeout")[0])
  
          if visibility_timeout > MAXIMUM_VISIBILTY_TIMEOUT:
              raise ValueError
  
          return visibility_timeout
docs: :raises ValueError: If specified visibility timeout exceeds MAXIMUM_VISIBILTY_TIMEOUT
          :raises TypeError: If visibility timeout was not specified