Optimize test suit runner by caching problem instances.
Optimize test suit runner by caching problem instances.

oaelhara/numbbo,oaelhara/numbbo,dtusar/coco,NDManh/numbbo,dtusar/coco,dtusar/coco,NDManh/numbbo,oaelhara/numbbo,dtusar/coco,dtusar/coco,oaelhara/numbbo,dtusar/coco,dtusar/coco,oaelhara/numbbo,NDManh/numbbo,NDManh/numbbo,dtusar/coco,oaelhara/numbbo,NDManh/numbbo,NDManh/numbbo,NDManh/numbbo,NDManh/numbbo,oaelhara/numbbo,NDManh/numbbo,oaelhara/numbbo,oaelhara/numbbo,dtusar/coco