96   virtual Status Close() { return Status::OK(); }  in Close()
97   virtual Status Flush() { return Status::OK(); }  in Flush()
98   virtual Status Sync() { return Status::OK(); }  in Sync()
100   virtual Status Append(const Slice& data) {  in Append()
102     return Status::OK();  in Append()
120   virtual Status Read(uint64_t offset, size_t n, Slice* result,  in Read()
123       return Status::InvalidArgument("invalid Read offset");  in Read()
130     return Status::OK();  in Read()
164     Status s = FinishImpl(options, *kvmap);  in Finish()
169   virtual Status FinishImpl(const Options& options, const KVMap& data) = 0;
190   virtual Status FinishImpl(const Options& options, const KVMap& data) {  in FinishImpl()
207     return Status::OK();  in FinishImpl()
230   virtual Status FinishImpl(const Options& options, const KVMap& data) {  in FinishImpl()
241     Status s = builder.Finish();  in FinishImpl()
296       status_ = Status::Corruption("malformed internal key");  in key()
303   virtual Status status() const {  in status()
308   mutable Status status_;
327   virtual Status FinishImpl(const Options& options, const KVMap& data) {  in FinishImpl()
338     return Status::OK();  in FinishImpl()
360   virtual Status FinishImpl(const Options& options, const KVMap& data) {  in FinishImpl()
371     return Status::OK();  in FinishImpl()
385     Status status = DestroyDB(name, options);  in NewDB()