Prado\Web\UI\ActiveControls\TCallbackPageStateTracker::trackChanges PHP Метод

    public function trackChanges()
    {
        foreach ($this->_states as $name => $value) {
            $obj = $this->_control->getViewState($name);
            $this->_existingState[$name] = is_object($obj) ? clone $obj : $obj;
        }
    }