why cant SslTransportLayer be muted before handshake completion?

[radai]

Hi,

as part of testing my code for KIP-72 (broker memory control), i ran into
the following code snippet in SslTransportLayer:

    public void removeInterestOps(int ops) {
        if (!key.isValid())
            throw new CancelledKeyException();
        else if (!handshakeComplete)
            throw new IllegalStateException("handshake is not completed");

        key.interestOps(key.interestOps() & ~ops);
    }

why cant an ssl socket be muted before handshake is complete?