code: function Pagelet(bigpipe) {
    if (!(this instanceof Pagelet)) return new Pagelet(bigpipe);
  
    var self = this;
  
    //
    // Create one single Fortress instance that orchestrates all iframe based client
    // code. This sandbox variable should never be exposed to the outside world in
    // order to prevent leaking.
    //
    this.sandbox = sandbox = sandbox || new Fortress();
    this.bigpipe = bigpipe;
  
    //
    // Add an initialized method which is __always__ called when the pagelet is
    // either destroyed directly, errored or loaded.
    //
    this.initialized = one(function initialized() {
      self.broadcast('initialized');
    });
  }
docs: Representation of a single pagelet.
  
  @constructor
  @param {BigPipe} bigpipe The BigPipe instance that was created.
  @api public