NioSslEngine implements NioFilter { synchronized void checkClosed() throws IOException { if (closed) { throw new IOException("NioSslEngine has been closed"); } } NioSslEngine(SSLEngine engine, BufferPool bufferPool); boolean handshake(SocketChannel socketChannel, int timeout,
      ByteBuffer peerNetData); @Override synchronized ByteBuffer wrap(ByteBuffer appData); @Override synchronized ByteBuffer unwrap(ByteBuffer wrappedBuffer); @Override ByteBuffer ensureWrappedCapacity(int amount, ByteBuffer wrappedBuffer,
      BufferType bufferType); @Override ByteBuffer readAtLeast(SocketChannel channel, int bytes,
      ByteBuffer wrappedBuffer); @Override ByteBuffer getUnwrappedBuffer(ByteBuffer wrappedBuffer); ByteBuffer ensureUnwrappedCapacity(int amount); @Override void doneReadingDirectAck(ByteBuffer unwrappedBuffer); @Override synchronized void close(SocketChannel socketChannel);  }
@Test public void checkClosed() throws Exception { nioSslEngine.checkClosed(); }