messages.getVertexIdMessageIterator();
while (iterator.hasNext()) {
iterator.next();
long vertexId = iterator.getCurrentVertexId().get();
double message = iterator.getCurrentMessage().get();
if (partitionMap.containsKey(vertexId)) {
reusableVertexId.set(vertexId);
reusableMessage.set(message);
reusableCurrentMessage.set(partitionMap.get(vertexId));
messageCombiner.combine(reusableVertexId, reusableCurrentMessage,
reusableMessage);