virtual bool SaveFile(const wxString &name, wxBitmapType type,
const wxPalette *palette = NULL) const = 0;
virtual bool LoadFile(const wxString &name, wxBitmapType type) = 0;
virtual bool SaveFile(const wxString &name, wxBitmapType type,
const wxPalette *palette = NULL) const = 0;
virtual bool LoadFile(const wxString &name, wxBitmapType type) = 0;