public List<DepartmentWithSalaryTotal> getAllDepartments() {
Collection<Department> departmentList = data.getDepartmentList();
List<DepartmentWithSalaryTotal> result = new ArrayList<DepartmentWithSalaryTotal>();
for (Department department : departmentList) {
List<Employee> employeeListForDepartment = data.getEmployeeListForDepartment(department.getId());
result.add(new DepartmentWithSalaryTotal(department, calculateTotalSalary(employeeListForDepartment)));
}
return result;
}