final String edgeInput = args.length > 1 ? args[1] : "";
final String output = args.length > 2 ? args[2] : "";
final char delimiter = args.length > 3 ? (char) Integer.parseInt(args[3]) : ',';
FileDataSource edges = new FileDataSource(new EdgeInputFormat(), edgeInput, "Input Edges");
edges.setParameter(EdgeInputFormat.ID_DELIMITER_CHAR, delimiter);
// =========================== Vertex Degree ============================
MapOperator projectEdge = MapOperator.builder(new ProjectEdge())