-show_message_part (GMimeObject *part, int *part_count,
- void (*show_part) (GMimeObject *part, int *part_count))
+show_message_part (GMimeObject *part,
+ int *part_count,
+ void (*show_part) (GMimeObject *part, int *part_count, int first),
+ void (*show_part_end) (GMimeObject *part),
+ int first)