@Override
  public List<List<O>> finish(Collection<? extends OutputWriter<O>> writers) {
    ImmutableList.Builder<List<O>> out = ImmutableList.builder();
    for (OutputWriter<O> w : writers) {
      InMemoryOutputWriter<O> writer = (InMemoryOutputWriter<O>) w;
      out.add(ImmutableList.copyOf(writer.getResult()));
    }
    return out.build();
  }
@ Override public List < List < O > > finish ( Collection < ? extends OutputWriter < O > > writers ) { ImmutableList . Builder < List < O > > out = ImmutableList . builder ( ) ; for ( OutputWriter < O > w : writers ) { InMemoryOutputWriter < O > writer = ( InMemoryOutputWriter < O > ) w ; out . add ( ImmutableList . copyOf ( writer . getResult ( ) ) ) ; } return out . build ( ) ; }
Returns a list of lists where the outer list has one element for each
reduce shard, which is a list of the values emitted by that shard, in
order.