@Override public void readFieldsRequest(DataInput input) throws IOException { int numPartitions = input.readInt(); partitionVertexData = new PairList<Integer, B>(); partitionVertexData.initialize(numPartitions); while (numPartitions-- > 0) { final int partitionId = input.readInt(); B vertexIdData = createVertexIdData(); vertexIdData.setConf(getConf()); vertexIdData.readFields(input); partitionVertexData.add(partitionId, vertexIdData); } }