Using fold method

PayrollService.kt

class PayrollService(private val employeeService: EmployeeService) {
    private val logger = LoggerFactory.getLogger(PayrollService::class.java)
    
    fun generatePayrollFor(employeeName: String): Either<Problem, Payroll> {
        return employeeService.findEmployeeByName(employeeName)
            .fold(
                { httpFailureProblem ->
                    logger.info("Could not fetch employee: ${httpFailureProblem.message()}")
                    httpFailureProblem.left()
                },
                { employee ->
                    buildPayrollForEmployee(employee)
                }
            )
    }

    data class Payroll(private val id: String,
                       private val employeeId: String,
                       private val salary: Float,
                       private val date: Date)
    
    private fun buildPayrollForEmployee(employee: Employee): Either<Problem, Payroll> {
        return Payroll(UUID.randomUUID().toString(), employee.id, employee.salary, Date()).right()
    }
}