// to be implemented in derived classes
virtual void DoInsertItems(const wxArrayString& items, int pos) = 0;
virtual void DoSetItems(const wxArrayString& items, void **clientData) = 0;
virtual void DoSetFirstItem(int n) = 0;
// to be implemented in derived classes
virtual void DoInsertItems(const wxArrayString& items, int pos) = 0;
virtual void DoSetItems(const wxArrayString& items, void **clientData) = 0;
virtual void DoSetFirstItem(int n) = 0;