@Override
    public String execute(CommandContext commandContext, String[] args) {
        if (args.length > 0) {
            return "Unsupported parameter " + Arrays.toString(args) + " for pwd.";
        }
        String service =
                commandContext.getRemote().attr(ChangeTelnet.SERVICE_KEY).get();
        StringBuilder buf = new StringBuilder();
        if (StringUtils.isEmpty(service)) {
            buf.append('/');
        } else {
            buf.append(service);
        }
        return buf.toString();
    }
@Test
    void testService() throws RemotingException {
        defaultAttributeMap
                .attr(ChangeTelnet.SERVICE_KEY)
                .set("org.apache.dubbo.rpc.protocol.dubbo.support.DemoService");
        String result = pwdTelnet.execute(mockCommandContext, new String[0]);
        assertEquals("org.apache.dubbo.rpc.protocol.dubbo.support.DemoService", result);
    }