@Override
    public ConsumerBuilder<T> priorityLevel(int priorityLevel) {
        checkArgument(priorityLevel >= 0, "priorityLevel needs to be >= 0");
        conf.setPriorityLevel(priorityLevel);
        return this;
    }
@Test(expectedExceptions = IllegalArgumentException.class)
    public void testConsumerBuilderImplWhenPriorityLevelPropertyIsNegative() {
        consumerBuilderImpl.priorityLevel(-1);
    }