$lineset->getSubDistrict()

Up: class CensusLineSet

This factory method returns instance of class SubDistrict corresponding to the sub-district identifiers passed to the constructor. If the SubDistrict parameter was a reference to an instance of SubDistrict, then this returns that same instance, otherwise it constructs an instance based upon the census, district, sub-district, and division identifiers.

Next: class CensusSet