protected function getCustomCastObject($attribute)
    {
        // Check if custom cast object already been set
        if (isset($this->customCastObjects[$attribute])) {
            return $this->customCastObjects[$attribute];
        }

        $customCastClass = $this->casts[$attribute];
        $customCastObject = new $customCastClass($this, $attribute);

        return $this->customCastObjects[$attribute] = $customCastObject;
    }