### Question:
ExponentialTaskExecutionBackOff implements TaskExecutionBackOff { public void setMultiplier(double multiplier) { checkMultiplier(multiplier); this.multiplier = multiplier; } ExponentialTaskExecutionBackOff();  ExponentialTaskExecutionBackOff(
      long initialInterval, long maxInterval, double multiplier, int maxRetries); long getInitialInterval(); void setInitialInterval(long initialInterval); int getMaxRetries(); void setMaxRetries(int maxRetries); double getMultiplier(); void setMultiplier(double multiplier); long getMaxInterval(); void setMaxInterval(long maxInterval); @Override long nextBackOff(Object object, RqueueMessage rqueueMessage, int failureCount); static final long DEFAULT_INITIAL_INTERVAL; static final double DEFAULT_MULTIPLIER; static final long DEFAULT_MAX_INTERVAL; }### Answer:
@Test public void setMultiplier() { ExponentialTaskExecutionBackOff e = new ExponentialTaskExecutionBackOff(); e.setMultiplier(1.2); assertEquals((long) (Math.pow(1.2, 3) * 1500), e.nextBackOff(null, null, 3)); assertEquals(1.2, e.getMultiplier(), 0.0001); }