presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/io/AccumuloPageSink.java/AccumuloPageSink/finish
class AccumuloPageSink:    @Override
    public CompletableFuture<Collection<Slice>> finish()
    {
        try {
            // Done serializing rows, so flush and close the writer and indexer
            writer.flush();
            writer.close();
            if (indexer.isPresent()) {
                indexer.get().close();
            }
        }
        catch (MutationsRejectedException e) {
            throw new PrestoException(UNEXPECTED_ACCUMULO_ERROR, "Mutation rejected by server on flush", e);
        }

        // TODO Look into any use of the metadata for writing out the rows
        return completedFuture(ImmutableList.of());
    }