code: def by_housing_units(self,
                           lower=-1,
                           upper=2 ** 31,
                           zipcode_type=ZipcodeType.Standard,
                           sort_by=SimpleZipcode.housing_units.name,
                           ascending=False,
                           returns=DEFAULT_LIMIT):
          
          return self.query(
              housing_units_lower=lower,
              housing_units_upper=upper,
              sort_by=sort_by, zipcode_type=zipcode_type,
              ascending=ascending, returns=returns,
          )
docs: Search zipcode information by house of units.