in src/com.jetbrains.youtrack.sdPlugin/libs/js/events.js [23:35]
pubSub: function pubSub() {
const subscribers = new Set();
const sub = fn => {
subscribers.add(fn);
return () => {
subscribers.delete(fn);
};
};
const pub = data => subscribers.forEach(fn => fn(data));
return Object.freeze({pub, sub});
}