class Department {
			ZZ_EXT_Department
			int deptNo;
			.......
	};
	class Employee {
			ZZ_EXT_Employee
			long salary, startingDate;
			.......
	};
	ZZ_HYPER_SINGLE_TREE(depts,Department);
	ZZ_HYPER_DOUBLE_AGGREGATE(empls,Department,Employee);
	ZZ_HYPER_NAME(emplName,Employee);
	ZZ_HYPER_UTILITIES(util);