platform/video.videojs/dist/video.es.js
function one(elem, type, fn) {
  if (Array.isArray(type)) {
    return _handleMultipleEvents(one, elem, type, fn);
  }
  var func = function func() {
    off(elem, type, func);
    fn.apply(this, arguments);
  };

  // copy the guid to the new function so it can removed using the original function's ID
  func.guid = fn.guid = fn.guid || newGUID();
  on(elem, type, func);
}
function one(elem, type, fn) {
  if (Array.isArray(type)) {
    return _handleMultipleEvents(one, elem, type, fn);
  }
  var func = function func() {
    off(elem, type, func);
    fn.apply(this, arguments);
  };

  // copy the guid to the new function so it can removed using the original function's ID
  func.guid = fn.guid = fn.guid || newGUID();
  on(elem, type, func);
}
Trigger a listener only once for an event

@param {Element|Object} elem
Element or object to bind to.

@param {string|string[]} type
Name/type of event

@param {Event~EventListener} fn
Event Listener function