private WriteFuture initiateClosure(NextFilter nextFilter, IoSession session)
throws SSLException {
SSLHandler handler = getSSLSessionHandler(session);
// if already shut down
if (!handler.closeOutbound()) {
return DefaultWriteFuture.newNotWrittenFuture(session);
}
// there might be data to write out here?
WriteFuture future = handler.writeNetBuffer(nextFilter);