int partitionId =
service.getVertexPartitionOwner(entry.getKey()).getPartitionId();
ByteArrayVertexIdMessages<IntWritable, IntWritable>
byteArrayVertexIdMessages =
new ByteArrayVertexIdMessages<IntWritable, IntWritable>(
new TestMessageValueFactory(IntWritable.class));
byteArrayVertexIdMessages.setConf(config);
byteArrayVertexIdMessages.initialize();
for (IntWritable message : entry.getValue()) {
byteArrayVertexIdMessages.add(entry.getKey(), message);
}