How to use the gudhi.EuclideanWitnessComplex function in gudhi

print("EuclideanWitnessComplex creation from points read in a OFF file")

        witnesses = gudhi.read_off(off_file=args.file)
        landmarks = gudhi.pick_n_random_points(
            points=witnesses, nb_points=args.number_of_landmarks
        )

        message = (
            "EuclideanWitnessComplex with max_edge_length="
            + repr(args.max_alpha_square)
            + " - Number of landmarks="
            + repr(args.number_of_landmarks)
        )
        print(message)

        witness_complex = gudhi.EuclideanWitnessComplex(
            witnesses=witnesses, landmarks=landmarks
        )
        simplex_tree = witness_complex.create_simplex_tree(
            max_alpha_square=args.max_alpha_square, limit_dimension=args.limit_dimension
        )

        message = "Number of simplices=" + repr(simplex_tree.num_simplices())
        print(message)

        diag = simplex_tree.persistence()

        print("betti_numbers()=")
        print(simplex_tree.betti_numbers())

        if args.no_diagram == False:
            gudhi.plot_persistence_diagram(diag, band=args.band)