+ virtual bool Open() APT_OVERRIDE { return false; }
+ virtual bool IsOpen() APT_OVERRIDE { return false; }
+ virtual bool Close() APT_OVERRIDE { return false; }
+ virtual bool InitHashes(HashStringList const &ExpectedHashes) APT_OVERRIDE;
+ virtual Hashes * GetHashes() APT_OVERRIDE;
+ virtual bool Die(FileFd * const /*File*/) APT_OVERRIDE { return false; }
+ virtual bool Flush(FileFd * const /*File*/) APT_OVERRIDE { return false; }
+ virtual bool Go(bool /*ToFile*/, FileFd * const /*File*/) APT_OVERRIDE { return false; }