aken by the connect timeout. If the connection time has not been
        established, a :exc:`~urllib3.exceptions.TimeoutStateError` will be
        raised.

        :return: Value to use for the read timeout.
        :rtype: int, float, :attr:`Timeout.DEFAULT_TIMEOUT` or None
        :raises urllib3.exceptions.TimeoutStateError: If :meth:`start_connect`
            has not yet been called on this object.
        Nr