revive() {
            $.console.assert(!this.loaded && !this._type, "[CacheRecord::revive] must not be called when loaded!");
            this._tiles = [];
            this._data = null;
            this._type = null;
            this.loaded = false;
            this._promise = null;
            this._destroyed = false;
        }
Set initial state, prepare for usage.
Must not be called on active cache, e.g. first call destroy().