/* Delete nodes that haven't been accessed since atime */
GisTile *gis_tile_gc(GisTile *root, time_t atime,
GisTileFreeFunc free_func, gpointer user_data);
/* Delete nodes that haven't been accessed since atime */
GisTile *gis_tile_gc(GisTile *root, time_t atime,
GisTileFreeFunc free_func, gpointer user_data);