code: public Optional<RelationReified> reified() {
          if (!relationStructure.isReified()) return Optional.empty();
          return Optional.of(relationStructure.reify());
      }
docs: Gets the RelationReified if the Relation has been reified.
  To reify the Relation you use RelationImpl.reify().
  NOTE: This approach is done to make sure that only write operations will cause the Relation to reify
  
  @return The RelationReified if the Relation has been reified