replace<T extends Object> method
替换为新数据 返回结构为旧数据如果不存在旧数据则返回null
Implementation
T? replace<T extends Object>({Object? key, required T data}) {
if (_isDestroyed) return null;
final k = _genKey<T>(key: key);
final last = _data[k] as T?;
_data[k] = data;
return last;
}