Custom super property management example

example.js

const customSuperProp = {};

function register(obj) {
  Object.assign(customSuperProp, obj);
}

function unregister(key) {
  delete customSuperProp[key];
}

function track(eventName, eventProperties) {
  mixpanel.track(eventName, Object.assign({}, customSuperProp, eventProperties));
}