Arguments variable in the Constructor Model

[hobophobik]

Hello,

I've been looking at the "Extending Ext for Newbies" Tutorial and have a fairly basic question...

In the superclass constructor call to apply, where does the variable "arguments" come from?

// MyPanel Extends Ext.Panel
MyPanel = Ext.extend(Ext.Panel, {
//  constructor function
    constructor: function(config) {
        Ext.apply(this, { 
            // Put your pre-configured config options here
            width: 300,
            height: 300
        });
        MyPanel.superclass.constructor.apply(this, arguments);
    }
}); 

Cheers,
Hobo