How to use the networkit.readGraph function in networkit

lblA, lblB = line.split()
            if lblA in lbl2idx and lblB in lbl2idx:
                idxA, idxB = (lbl2idx[i] for i in line.split())
                # always go from smaller -> larger, helps merge
                if(idxA > idxB):
                    (idxA, idxB) = (idxB, idxA)
                if idxA not in problem:
                    problem[idxA] = []
                problem[idxA].append(idxB)

    if verbose:
        print("Loaded ", count, " prob pairs.")
        print("Grouped into ", len(problem), " query groups.")
        print("Constructing network from ", edgePath)

    graph = nk.readGraph(edgePath, nk.Format.EdgeListSpaceZero)
    outLock = Lock()
    outFile = open(outPath, "w")

    with ThreadPool() as pool:
        pool.map(runProbGroup, problem.items())

    outFile.close()

def graphMeta(graphNames, graphDir, fileEnding=".gml.graph", graphFormat=networkit.Format.GML):
	if not have_pandas:
		raise MissingDependencyError("pandas")
	meta = []
	for name in graphNames:
		info("loading {name}".format(**locals()))
		G = networkit.readGraph(os.path.join(graphDir, "{0}{1}".format(name, fileEnding)), graphFormat)
		(n, m) = G.size()
		meta.append({"name" : name, "n" : n, "m" : m})
	info("done")
	return pandas.DataFrame(meta, columns=["name", "n", "m"])

"""

	# if no custom config is given, use a preconfigured config according to preset name
	if not config:
		config = Config.createConfig(preset)

	if not os.path.isdir(outputDir):
		os.mkdir(outputDir)

	for (dirpath, dirnames, filenames) in os.walk(inputDir):
		for filename in filenames:
			file = dirpath + "/" + filename
			if fnmatch.fnmatch(filename, filePattern):
				Profile.verbosePrint("\n[ " + file + " ]")
				try:
					G = kit.readGraph(file, graphFormat)
					try:
						pf = Profile.create(
							G,
							config = config
						)
						Profile.verbosePrint("");
						pf.output(
							outputType = outputType,
							directory = outputDir,
							style = style,
							color = color,
							parallel = parallel
						)
					except Exception as e:
						Profile.verbosePrint("=> an error occured: {0} of type {1}".format(e, type(e)))
						Profile.verbosePrint(traceback.format_exc())

def loadGraph(self, path, graphFormat=networkit.Format.GML):
		with Timer() as t:
			G = networkit.readGraph(path, graphFormat)
		debug("reading {path} took {t.elapsed} s".format(**locals()))
		return G