code: def run_co_clustering(self):
      self.co_clustering = PaCo(
          self.train_file,
          k_row=self.k_row,
          l_col=self.l_col,
          density_low=self.density_low,
      )
      self.co_clustering.fit()
      if len(self.co_clustering.density) == 1:
          raise ValueError(
              "Error: Co-clustering generated only 1 bi-cluster!"
          )
  
file_path: CaseRecommender/caserec/recommenders/item_recommendation/paco_recommender.py
imports: from collections import defaultdict
  import numpy
  from caserec.clustering.paco import PaCo
  from caserec.evaluation.item_recommendation import ItemRecommendationEvaluation
  from caserec.utils.process_data import ReadFile
label_desc: Use image node_id 2 for calling the PaCoRecommender obj's underlying member method code with example usage: obj.run_co_clustering() without return types