code: function PopupMonitor() {
  	this.intervals = {};
  	this.monitorInterval = null;
  	this.windowInstance = null;
  	this.onMessage = messageEvent => {
  		if ( messageEvent.source === this.windowInstance ) {
  			this.emit( 'message', messageEvent.data );
  		}
  	};
  }
docs: PopupMonitor component
  
  @public