Function promisify

static/word2md/mammoth.browser.js:7943–7946

(callback, receiver, multiArgs)

}

function promisify(callback, receiver, multiArgs) {
    return makeNodePromisified(callback, receiver, undefined,
                                callback, null, multiArgs);
}

Promise.promisify = function (fn, options) {
    if (typeof fn !== "function") {