/** @brief Remove the last element from partition_vector effectively
  *          reducing the size by one. The removed element is destroyed.
  */
 void pop_back()
 {
     partition_vector_.pop_back();
 }
 /// Remove the last element from partitioned_vector_partition effectively
 /// reducing the size by one. The removed element is destroyed.
 ///
 void pop_back()
 {
     partitioned_vector_partition_.pop_back();
 }