### Question:
HiveDifferences { public static Builder builder(DiffListener diffListener) { return new Builder(diffListener); } private  HiveDifferences(
      ComparatorRegistry comparatorRegistry,
      DiffListener diffListener,
      Table sourceTable,
      Iterator<Partition> sourcePartitionIterator,
      Optional<Table> replicaTable,
      Optional<? extends PartitionFetcher> replicaPartitionFetcher,
      Function<Path, String> checksumFunction,
      int partitionLimit); static Builder builder(DiffListener diffListener); void run();  }### Answer:
@Test(expected = IllegalStateException.class) public void requiredPartitionFetcher() { HiveDifferences .builder(diffListener) .comparatorRegistry(comparatorRegistry) .source(sourceConfiguration, sourceTable, sourcePartitionIterable) .replica(Optional.of(replicaTable), Optional.<PartitionFetcher> absent()) .checksumFunction(checksumFunction) .build(); }