@Test
  public void testMileage() throws Exception {
    Appointment app =
        new Appointment(null)
            .setStart(DateTime.now())
            .setNurse(new Nurse(null).setMileageRate(.5))
            .setPatient(new Patient(null).setVendor(new Vendor(null).setMileageRate(.4)));

    // If we set no mileage there should be no mileage.
    assertEquals(0, app.getMileage(), .0001);
    assertEquals(0, app.getPayMileage(), .0001);
    assertEquals(0, app.getBillingMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);

    // Setting the Driven Miles less than 20 will result in the pay/billable being zero
    app.setMileageD(10);
    assertEquals(10, app.getMileage(), .0001);
    assertEquals(0, app.getPayMileage(), .0001);
    assertEquals(0, app.getBillingMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);

    // Setting the Driven Miles greater than 20 will result in the pay/billable being (driven - 20)
    app.setMileageD(25);
    assertEquals(25, app.getMileage(), .0001);
    assertEquals(5, app.getPayMileage(), .0001);
    assertEquals(5, app.getBillingMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);

    // Setting the billable miles will override the payable miles if not set.
    app.setBillingMileageD(20);
    assertEquals(25, app.getMileage(), .0001);
    assertEquals(20, app.getBillingMileage(), .0001);
    assertEquals(20, app.getPayMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);

    // Setting the payable miles will override the billable miles if not set.
    app.setBillingMileageD(-1);
    app.setPayMileageD(15);
    assertEquals(25, app.getMileage(), .0001);
    assertEquals(15, app.getBillingMileage(), .0001);
    assertEquals(15, app.getPayMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);

    // You can zero out pay and billable if you like.
    app.setBillingMileageD(0);
    app.setPayMileageD(0);
    assertEquals(25, app.getMileage(), .0001);
    assertEquals(0, app.getBillingMileage(), .0001);
    assertEquals(0, app.getPayMileage(), .0001);
    assertEquals(.5, app.getPayMileageRate(), .0001);
    assertEquals(.4, app.getBillingMileageRate(), .0001);
  }