protected static short EvaluateMaxFragmentLengthExtension(bool resumedSession, IDictionary clientExtensions, IDictionary serverExtensions, byte alertDescription)
    {
        short maxFragmentLengthExtension = TlsExtensionsUtilities.GetMaxFragmentLengthExtension(serverExtensions);

        if (maxFragmentLengthExtension >= 0 && (!MaxFragmentLength.IsValid((byte)maxFragmentLengthExtension) || (!resumedSession && maxFragmentLengthExtension != TlsExtensionsUtilities.GetMaxFragmentLengthExtension(clientExtensions))))
        {
            throw new TlsFatalAlert(alertDescription);
        }
        return(maxFragmentLengthExtension);
    }