public GraphChiEngine(String baseFilename, int nShards) throws FileNotFoundException, IOException {
this.baseFilename = baseFilename;
this.nShards = nShards;
loadIntervals();
blockManager = new DataBlockManager();
degreeHandler = new DegreeData(baseFilename);
File vertexIdTranslateFile = new File(ChiFilenames.getVertexTranslateDefFile(baseFilename, nShards));
if (vertexIdTranslateFile.exists()) {
vertexIdTranslate = VertexIdTranslate.fromFile(vertexIdTranslateFile);
} else {