platform/video.videojs/dist/video.es.js
function bind(context, fn, uid) {
  // Make sure the function has a unique ID
  if (!fn.guid) {
    fn.guid = newGUID();
  }

  // Create the new function that changes the context
  var bound = function bound() {
    return fn.apply(context, arguments);
  };

  // Allow for the ability to individualize this function
  // Needed in the case where multiple objects might share the same prototype
  // IF both items add an event listener with the same function, then you try to remove just one
  // it will remove both because they both have the same guid.
  // when using this, you need to use the bind method when you remove the listener as well.
  // currently used in text tracks
  bound.guid = uid ? uid + '_' + fn.guid : fn.guid;

  return bound;
}
function bind(context, fn, uid) {
  // Make sure the function has a unique ID
  if (!fn.guid) {
    fn.guid = newGUID();
  }

  // Create the new function that changes the context
  var bound = function bound() {
    return fn.apply(context, arguments);
  };

  // Allow for the ability to individualize this function
  // Needed in the case where multiple objects might share the same prototype
  // IF both items add an event listener with the same function, then you try to remove just one
  // it will remove both because they both have the same guid.
  // when using this, you need to use the bind method when you remove the listener as well.
  // currently used in text tracks
  bound.guid = uid ? uid + '_' + fn.guid : fn.guid;

  return bound;
}
@file fn.js
@module fn
 
Bind (a.k.a proxy or Context). A simple method for changing the context of a function
It also stores a unique id on the function so it can be easily removed from events.

@param {Mixed} context
The object to bind as scope.

@param {Function} fn
The function to be bound to a scope.

@param {number} [uid]
An optional unique ID for the function to be set

@return {Function}
The new function that will be bound into the context given