extern BI_open shell_back_open;
extern BI_close shell_back_close;
extern BI_destroy shell_back_destroy;
extern BI_db_init shell_back_db_init;
extern BI_db_destroy shell_back_db_destroy;
extern BI_open shell_back_open;
extern BI_close shell_back_close;
extern BI_destroy shell_back_destroy;
extern BI_db_init shell_back_db_init;
extern BI_db_destroy shell_back_db_destroy;