code: def __update_cluster_dendrogram(self, index_cluster, blocks):
          
          if len(self.__dendrogram) <= index_cluster:
              self.__dendrogram.append([])
  
          blocks = sorted(blocks, key=lambda block: block.get_density(), reverse=True)
          self.__dendrogram[index_cluster] += blocks
docs: !
          @brief Append clustered blocks to dendrogram.
  
          @param[in] index_cluster (uint): Cluster index that was assigned to blocks.
          @param[in] blocks (list): Blocks that were clustered.