65 class VersionSet;  variable
563   friend class VersionSet;  variable
685   VersionSet* version_set() { return vset_; }  in version_set()
701   friend class VersionSet;  variable
739   VersionSet* vset_;            // VersionSet to which this Version belongs
750   Version(ColumnFamilyData* cfd, VersionSet* vset, const FileOptions& file_opt,
812 class VersionSet {
814   VersionSet(const std::string& dbname, const ImmutableDBOptions* db_options,
820   VersionSet(const VersionSet&) = delete;
821   void operator=(const VersionSet&) = delete;
823   virtual ~VersionSet();
1221 class ReactiveVersionSet : public VersionSet {
1249   using VersionSet::ApplyOneVersionEditToBuilder;
1268   using VersionSet::LogAndApply;
1269   using VersionSet::Recover;