code: def __calculate_cluster_difference(self, index_cluster, difference):
          
          cluster_difference = 0.0
          for index_point in self.__clusters[index_cluster]:
              cluster_difference += difference[index_point]
  
          return cluster_difference
docs: !
          @brief Calculates distance from each object in specified cluster to specified object.
  
          @param[in] index_point (uint): Index point for which difference is calculated.
  
          @return (list) Distance from specified object to each object from input data in specified cluster.