code: def __calculate_nearest_distance(self, index_cluster1, index_cluster2):
          
          candidate_minimum_distance = float('Inf');
          
          for index_object1 in self.__clusters[index_cluster1]:
              for index_object2 in self.__clusters[index_cluster2]:
                  distance = euclidean_distance_square(self.__pointer_data[index_object1], self.__pointer_data[index_object2]);
                  if (distance < candidate_minimum_distance):
                      candidate_minimum_distance = distance;
          
          return candidate_minimum_distance;
docs: !
          @brief Finds two nearest objects in two specified clusters and returns distance between them.
          
          @param[in] (uint) Index of the first cluster.
          @param[in] (uint) Index of the second cluster.
          
          @return The nearest euclidean distance between two clusters.