Prevent responder from getting new requests

Hi, I'm working on my service to graceful shutdown. How can I prevent responder to accept new requests so it could finish already got ones and then call responder.close?

I have example responder:

const cote = require('cote');

const { SHOULD_SIGTERM } = process.env;

async function main() {
    const server = new cote.Responder({
        name: 'rpc-server',
        namespace: 'rpc-server',
        key : 'rpc-server'
    });

    server.on('foo', async ({ type, data }) => {
        const { i } = data;

        if (SHOULD_SIGTERM && i === 5) {
            server.close();
        }

        console.log('Data', i);
        const result = `bar-${i}`;
        console.log('Result', result);

        return result;
    })
}

if (require.main === module) {
    main();
}

and example requester that make 10 requests:

const cote = require('cote');

async function main() {
    const requester = new cote.Requester({
        name: 'rpc-requester',
        namespace: 'rpc-server',
        key: 'rpc-server',
    });

    for (let i = 0; i < 10; i++) {
        let result;
        try {
            result = await requester.send({
                type: 'foo',
                data: {
                    i,
                },
                __timeout: 3 * 1000
            });
        } catch (e) {
            console.error(e);
        }
        console.log('Result', result);
    }

    requester.close();
}

if (require.main === module) {
    main();
}

As I coded responder to close on request with i === 5, I lose this request. IMPORTANT NOTE: when I do NOT specify __timeout in requester, once responder is restarted this request hangs forever. In case when I do NOT call responder.close untill all requests are processed I keep getting new requests, so it does not seems like a solution. Thanks in advance.