@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (!(o instanceof TtlBucket)) {
      return false;
    }
    TtlBucket that = (TtlBucket) o;
    return mTtlIntervalStartTimeMs == that.mTtlIntervalStartTimeMs;
  }
@Test
  public void equals() {
    TtlBucket firstBucket = new TtlBucket(0);
    TtlBucket secondBucket = new TtlBucket(0);
    TtlBucket thirdBucket = new TtlBucket(1);

    Assert.assertNotEquals(firstBucket, null);
    Assert.assertEquals(firstBucket, firstBucket);
    Assert.assertEquals(firstBucket, secondBucket);
    Assert.assertEquals(secondBucket, firstBucket);
    Assert.assertNotEquals(firstBucket, thirdBucket);
  }