assertThat(shardIterator.firstOrNull(), sameInstance(shardIterator.firstOrNull()));
assertThat(shardIterator.remaining(), equalTo(2));
ShardRouting shardRouting1 = shardIterator.nextOrNull();
assertThat(shardRouting1, notNullValue());
assertThat(shardIterator.remaining(), equalTo(1));
ShardRouting shardRouting2 = shardIterator.nextOrNull();
assertThat(shardRouting2, notNullValue());
assertThat(shardIterator.remaining(), equalTo(0));
assertThat(shardRouting2, not(sameInstance(shardRouting1)));
assertThat(shardIterator.nextOrNull(), nullValue());
assertThat(shardIterator.remaining(), equalTo(0));