### Question:
BucketsEquivalence extends Equivalence<Buckets> { @Override protected int doHash(Buckets buckets) { final int prime = 31; int result = 1; List<Bucket> bucketList = buckets.getBucket(); Set<Bucket> bucketSet = new HashSet<>(); if (bucketList != null) { bucketSet = new HashSet<>(bucketList); } result = prime * result + bucketSet.hashCode(); return result; } BucketsEquivalence();   }### Answer:
@Test public void testDoHash() { Buckets a = new BucketsBuilder().build(); eq.doHash(a); }