Process a particular binding and fire the handler if necessary.
@private
@param {Object} binding The binding information
@param {Ext.EventObject} event
function(binding, event){
        if (this.checkModifiers(binding, event)) {
            var key = event.getKey(),
                handler = binding.fn || binding.handler,
                scope = binding.scope || this,
                keyCode = binding.keyCode,
                defaultEventAction = binding.defaultEventAction,
                i,
                len,
                keydownEvent = new Ext.EventObjectImpl(event);


            for (i = 0, len = keyCode.length; i < len; ++i) {
                if (key === keyCode[i]) {
                    if (handler.call(scope, key, event) !== true && defaultEventAction) {
                        keydownEvent[defaultEventAction]();
                    }
                    break;
                }
            }
        }
    }