code: @Override
      protected NioSessionEx accept(IoProcessor<NioSessionEx> processor,
              ServerSocketChannel handle) throws Exception {
  
          SelectionKey key = handle.keyFor(selector);
  
          if ((key == null) || (!key.isValid()) || (!key.isAcceptable())) {
              return null;
          }
  
          // accept the connection from the client
          SocketChannel ch = handle.accept();
  
          if (ch == null) {
              return null;
          }
  
          final NioSocketSessionEx session = new NioSocketSessionEx(this, processor, ch);
  
          try {
              session.initSessionConfig();
              return session;
          } catch (RuntimeIoException e) {
              if (AbstractIoSessionConfig.REPORT_SESSION_CONFIG_FAILURE) {
                  throw e;
              }
              if (LOGGER.isDebugEnabled()) {
                  LOGGER.debug("Unexpected exception initializing session " +
                               "TCP options. Rejecting connection.", e);
              }
              return null;
          }
      }
docs: {@inheritDoc}