void                              seek(PRSeekWhence whence, PRInt64 offset)
void                              seek(PRInt64 offset)
    void                              seek(PRSeekWhence whence, PRInt64 offset)                                      {                                          set_at_eof(PR_FALSE);                                          if (mStore)                                              mResult = mStore->Seek(whence, offset);                                      }