virtual wxArchiveEntry *DoNewEntry() const = 0;
virtual wxArchiveInputStream *DoNewStream(wxInputStream& stream) const = 0;
virtual wxArchiveOutputStream *DoNewStream(wxOutputStream& stream) const = 0;
virtual wxArchiveEntry *DoNewEntry() const = 0;
virtual wxArchiveInputStream *DoNewStream(wxInputStream& stream) const = 0;
virtual wxArchiveOutputStream *DoNewStream(wxOutputStream& stream) const = 0;