public function getDiffReplacements()
    {
        $data = array();
        foreach ($this->getSafeAttributes() as $attribute) {
            if ($attribute->isReplaced()) {
                $data[$attribute->getName()] = $attribute->getValues();
            }
        }
        foreach ($this->tracker->getReplacements() as $name) {
            $data[$name] = $this->get($name)->getValues();
        }
        return $data;
    }