有一个StoreRequest有一对字段和非图像加载，我怎样才能在编辑时忽略这些条件？

Question

There is a StoreRequest there is a pair of field and non-image loading, how can I ignore these conditions when editing?

 public function rules()
    {
        return [
            'title' => 'required|unique',
            'image' => 'required|mimes:jpg,jpeg,png'
        ];
    }