250 struct ReferenceIterator {  struct
251   Data* data;
252   uint64_t sequence;  // ignore entries with sequence number below this
254   bool valid = false;
255   std::string key;
256   std::string value;
258   ReferenceIterator(Data* _data, uint64_t _sequence)  in ReferenceIterator()  argument
261   bool Valid() const { return valid; }  in Valid()
269   bool FindNextKey(bool skip, bool forward) {  in FindNextKey()
294   bool FindValueForCurrentKey() {  in FindValueForCurrentKey()
363   void DoTheThing(bool skip, bool forward) {  in DoTheThing()
369   void Seek(const Slice& target) {  in Seek()
373   void SeekForPrev(const Slice& target) {  in SeekForPrev()
377   void SeekToFirst() { Seek(""); }  in SeekToFirst()
378   void SeekToLast() {  in SeekToLast()
382   void Next() {  in Next()
386   void Prev() {  in Prev()