CassandraDefaultBucketDAO { Mono<ByteBuffer> readPart(BlobId blobId, int position) { return cassandraAsyncExecutor.executeSingleRow( selectPart.bind() .setString(DefaultBucketBlobParts.ID, blobId.asString()) .setInt(DefaultBucketBlobParts.CHUNK_NUMBER, position)) .map(this::rowToData); } @Inject @VisibleForTesting  CassandraDefaultBucketDAO(Session session);   }
@Test void readPartShouldReturnEmptyWhenNone() { Optional<ByteBuffer> maybeBytes = testee.readPart(BLOB_ID, POSITION).blockOptional(); assertThat(maybeBytes).isEmpty(); }