lib/Ext/event/publisher/Dom.js
function(target, eventName) {
        if (!this.handles(eventName)) {
            return false;
        }

        var match = target.match(this.idOrClassSelectorRegex),
            subscribers = this.getSubscribers(eventName),
            type, value;

        if (match !== null) {
            type = match[1];
            value = match[2];

            if (type === '#') {
                return subscribers.id.hasOwnProperty(value);
            }
            else {
                return subscribers.className.hasOwnProperty(value);
            }
        }
        else {
            return (subscribers.selector.hasOwnProperty(target) && Ext.Array.indexOf(subscribers.selector, target) !== -1);
        }

        return false;
    }
function(target, eventName) {
        if (!this.handles(eventName)) {
            return false;
        }

        var match = target.match(this.idOrClassSelectorRegex),
            subscribers = this.getSubscribers(eventName),
            type, value;

        if (match !== null) {
            type = match[1];
            value = match[2];

            if (type === '#') {
                return subscribers.id.hasOwnProperty(value);
            }
            else {
                return subscribers.className.hasOwnProperty(value);
            }
        }
        else {
            return (subscribers.selector.hasOwnProperty(target) && Ext.Array.indexOf(subscribers.selector, target) !== -1);
        }

        return false;
    }
<debug>