What does the this.mon() function do?

mon.js

demos.TouchImpl.TouchPad = Ext.extend(Ext.Component, {
    id: 'touchpad',
    html: 'Touch here!',

    initComponent : function() {
        this.addEvents('log');
        demos.TouchImpl.TouchPad.superclass.initComponent.call(this);
    },

    afterRender: function() {
        demos.TouchImpl.TouchPad.superclass.afterRender.call(this);

        this.mon(this.el, {
            touchstart: this.handleEvent,
            touchend: this.handleEvent,
            touchmove: this.handleEvent,
            touchdown: this.handleEvent,
            scrollstart: this.handleEvent,
            scroll: this.handleEvent,
            scrollend: this.handleEvent,
            singletap: this.handleEvent,
            tap: this.handleEvent,
            doubletap: this.handleEvent,
            taphold: this.handleEvent,
            tapcancel: this.handleEvent,
            swipe: this.handleEvent,
            pinch: this.handleEvent,
            pinchstart: this.handleEvent,
            pinchend: this.handleEvent,
            scope: this
        });
    },

    handleEvent: function(e) {
        this.fireEvent('log', e.type, e);
    }
});