// -------------------------------------------------------------------------
  // creates a simple provider
  private SimpleRatesProvider createProvider(ExpandedFra fraExp) {
    DiscountFactors mockDf = mock(DiscountFactors.class);
    IborIndexRates mockIbor = mock(IborIndexRates.class);
    SimpleRatesProvider prov = new SimpleRatesProvider(VAL_DATE, mockDf);
    prov.setIborRates(mockIbor);

    IborRateObservation obs = (IborRateObservation) fraExp.getFloatingRate();
    IborRateSensitivity sens = IborRateSensitivity.of(obs.getIndex(), obs.getFixingDate(), 1d);
    when(mockIbor.ratePointSensitivity(obs.getFixingDate())).thenReturn(sens);
    when(mockIbor.rate(obs.getFixingDate())).thenReturn(FORWARD_RATE);

    when(mockDf.discountFactor(fraExp.getPaymentDate())).thenReturn(DISCOUNT_FACTOR);
    return prov;
  }
  /** Test present value sensitivity for ISDA */
  public void test_presentValueSensitivity_ISDA() {
    RateObservationFn<RateObservation> mockObs = mock(RateObservationFn.class);
    DiscountFactors mockDf = mock(DiscountFactors.class);
    SimpleRatesProvider simpleProv = new SimpleRatesProvider(VAL_DATE, mockDf);

    ExpandedFra fraExp = FRA.expand();
    double forwardRate = 0.05;
    double discountRate = 0.015;
    double paymentTime = 0.3;
    double discountFactor = Math.exp(-discountRate * paymentTime);
    LocalDate fixingDate = FRA.getStartDate();
    PointSensitivityBuilder sens = IborRateSensitivity.of(FRA.getIndex(), fixingDate, 1d);
    when(mockDf.discountFactor(fraExp.getPaymentDate())).thenReturn(discountFactor);
    when(mockDf.zeroRatePointSensitivity(fraExp.getPaymentDate()))
        .thenReturn(
            ZeroRateSensitivity.of(
                fraExp.getCurrency(), fraExp.getPaymentDate(), -discountFactor * paymentTime));
    when(mockObs.rateSensitivity(
            fraExp.getFloatingRate(), fraExp.getStartDate(), fraExp.getEndDate(), simpleProv))
        .thenReturn(sens);
    when(mockObs.rate(fraExp.getFloatingRate(), FRA.getStartDate(), FRA.getEndDate(), simpleProv))
        .thenReturn(forwardRate);
    DiscountingFraProductPricer test = new DiscountingFraProductPricer(mockObs);
    PointSensitivities sensitivity = test.presentValueSensitivity(fraExp, simpleProv);
    double eps = 1.e-7;
    double fdDscSense = dscSensitivity(FRA, forwardRate, discountFactor, paymentTime, eps);
    double fdSense = presentValueFwdSensitivity(FRA, forwardRate, discountFactor, eps);

    ImmutableList<PointSensitivity> sensitivities = sensitivity.getSensitivities();
    assertEquals(sensitivities.size(), 2);
    IborRateSensitivity sensitivity0 = (IborRateSensitivity) sensitivities.get(0);
    assertEquals(sensitivity0.getIndex(), FRA.getIndex());
    assertEquals(sensitivity0.getFixingDate(), fixingDate);
    assertEquals(sensitivity0.getSensitivity(), fdSense, FRA.getNotional() * eps);
    ZeroRateSensitivity sensitivity1 = (ZeroRateSensitivity) sensitivities.get(1);
    assertEquals(sensitivity1.getCurrency(), FRA.getCurrency());
    assertEquals(sensitivity1.getDate(), fraExp.getPaymentDate());
    assertEquals(sensitivity1.getSensitivity(), fdDscSense, FRA.getNotional() * eps);

    // test via FraTrade
    DiscountingFraTradePricer testTrade = new DiscountingFraTradePricer(test);
    assertEquals(
        testTrade.presentValueSensitivity(FRA_TRADE, simpleProv),
        test.presentValueSensitivity(fraExp, simpleProv));
  }