function(type) {
        return Focusable._domForEvent.call(this, type) ||
            Container.prototype.domForEvent.call(this, type);
    }
function(type) {
        return Focusable._domForEvent.call(this, type) ||
            Container.prototype.domForEvent.call(this, type);
    }
function ( type ) { return Focusable . _domForEvent . call ( this , type ) || Container . prototype . domForEvent . call ( this , type ) ; }
store original version function so we can instance override _update in throttle and debounce and then revert back
store original version function so we can instance override _update in throttle and debounce and then revert back