Read gowalla dataset done! u_num: 29858, i_num: 40981
Load a pre-trained model
 UL AUC before unlearning: 0.5004
ACC AUC before unlearning: 0.8984
NDCG@20 before unlearning: 0.0856
Start phantom user assignment k-means!
Finish phantom user assignment k-means!
