SOURCE

const chunkSize=1;
const getHeaders = ((initNum=0) =>
    (num=initNum) => {
        console.log(num);
        const chunk = chunkSize * 1024 * 1024;

        let headers = {
            'If-Range': new Date(),
            Range: `bytes=0-${chunk}`,
            'content-type': 'application/x-www-form-urlencoded;charset=utf-8'
        };

        if (num) {
            const startWith = chunk * num+1;
            const endWith = chunk * (num + 1);
            headers = {
                'If-Range': new Date(),
                Range: `bytes=${startWith}-${endWith}`,
                'content-type': 'application/x-www-form-urlencoded;charset=utf-8'
            };
        }
        initNum++;
        return headers;
    }
)()
console.log(getHeaders())
console.log(getHeaders())
console.log(getHeaders())