 		int vwsize = 32;
 		int threads = 1;
 		long long arbparam = 0;
+		bool nonDirectedGraph = false;		// By default, the graph is directed.
 
 		/********************************
 		 * GETTING INPUT PARAMETERS.

				vwsize = std::atoi( argv[iii+1] );
			else if( !strcmp( argv[iii], "--arbparam" ) && iii != argc-1 /*is not the last one*/)
				arbparam = std::atoll( argv[iii+1] );

		if( !inputFile.is_open() || procesingMethod == UNSPECIFIED ) {
			std::cerr << "Usage: " << usage;

		uint nEdges = parse_graph::parse(
				inputFile,		// Input file.
				parsedGraph,	// The parsed graph.
				arbparam,
				nonDirectedGraph );		// Arbitrary user-provided parameter.
		std::cout << "Input graph collected with " << parsedGraph.size() << " vertices and " << nEdges << " edges.\n";


