def OpenAddContactDialog(self, Username=''):
        self.OpenDialog('ADDAFRIEND', Username)
Recommend new items for all users in the training dataset.  Assumes
dataset/ETHPy150Open Skype4Py/Skype4Py/Skype4Py/client.py/Client.OpenAddContactDialog--crossover with--dataset/ETHPy150Open Mendeley/mrec/mrec/reranking_recommender.py/RerankingRecommender.batch_recommend_items