code: public final TcpServer handle(BiFunction<? super NettyInbound, ? super
  			NettyOutbound, ? extends Publisher<Void>> handler) {
  		return new TcpServerHandle(this, handler);
  	}
docs: Attaches an I/O handler to react on a connected client
  
  @param handler an I/O handler that can dispose underlying connection when
  {@link Publisher} terminates.
  
  @return a new {@link TcpServer}