How to enable ocsp in web socket

I used wb with https and express. Still I get ocsp respond from the ocsp server even I enable ocsp stapling. How to enable it. I coud not figure out it.
This is my code.

```
var WebSocket = require('ws');
var https = require('https');
var ocsp = require('ocsp');

var bodyparser = require('body-parser');
var express = require('express');
var app = express();

app.use(bodyparser.json());
var PORT = 8080;

var ocspCache = new ocsp.Cache();

var server = new https.createServer({
cert: fs.readFileSync(`${__dirname}/pki/server/certs/server.cert.pem`),
key: fs.readFileSync(`${__dirname}/pki/server/private/server.key.pem`),
ca: [
fs.readFileSync(`${__dirname}/pki/intermediate/certs/ca-chain.cert.pem`)
],
requestCert: true,
rejectUnauthorized: true
}, app);

var wss = new WebSocket.Server({
server
});

wss.on('connection', function connection(ws, req) {

var cert = req.socket.getPeerCertificate(true);
var rawCert = cert.raw;
var rawIssuer = cert.issuerCertificate.raw;

ocsp.getOCSPURI(rawCert, function(err, uri) {
if (err) console.log(err);
var req = ocsp.request.generate(rawCert, rawIssuer);
var options = {
url: uri,
ocsp: req.data
};
ocspCache.request(req.id, options, null);
});

ws.on('message', function incoming(message) {
console.log(ocspCache.cache);
ocsp.check({cert: rawCert, issuer: rawIssuer}, function(err, res) {
if(err) {
console.log(err.message);
ws.send('Failed to obtain OCSP response!');
} else {
console.log(res.type);
var status = res.type;
if(status == 'good'){
console.log('Received: %s', message);
ws.send('Hello from server!');
}else{
ws.send('Certificate is revoked!');
}
}
});
});
});

server.listen(PORT, ()=>{
console.log( (new Date()) + " Server is listening on port " + PORT);
});
```
@indutny

Start with the HTTPS server, WebSocket setup, and OCSP calls shown in the issue, then read the project's stapling and checking APIs. Determine whether the requested behavior is supported and document the required configuration or limitation; the issue is done when the enablement steps or limitation are clearly explained.

Written by the indexing model from the issue text.