ContractorCalculator.java

package payroll;

public class ContractorCalculator extends PayCalculator {
  public ContractorCalculator() {
    super(false);
  }
}

HourlyCalculator.java

package payroll;

public class HourlyCalculator extends PayCalculator {
  public HourlyCalculator() {
    super(true);
  }
}

PayCalculatorTest.java

public class PayCalculatorTest {
  private PayCalculator hourlyCalculator = new HourlyCalculator();
  private PayCalculator contractorCalculator = new ContractorCalculator();