code: def search_new_items(self):
      for i in self.test_set["items"]:
          if i not in self.train_set["items"]:
              self.new_items.add(i)
  
file_path: CaseRecommender/caserec/recommenders/rating_prediction/item_msmf.py
imports: import numpy
  from caserec.recommenders.rating_prediction.matrixfactorization import MatrixFactorization
  from caserec.utils.extra_functions import timed
label_desc: Use image node_id 4 for calling the ItemMSMF obj's underlying member method code with example usage: obj.search_new_items() without return types