You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: dimacs10_demo.m
    path of file: ./repos/SuiteSparse/MATLAB_Tools/dimacs10
    
    the code of the file until where you have to start completion: function dimacs10_demo (arg)
%DIMACS10_DEMO reads in the DIMACS10 graphs.

    
function dimacs10_demo (arg)
%DIMACS10_DEMO reads in the DIMACS10 graphs.
% Reads them in and displays them in increasing order of nnz(S).
% Can also read in just a subset.
%
% Example
%   dimacs10_demo
%   dimacs10_demo (-10) ;           % just the smallest 10 graphs
%   dimacs10_demo ([1 3 5 8]) ;     % read just those four graphs
%
% See also dimacs10, ssget

% DIMACS10, Copyright (c) 2011, Timothy A Davis. All Rights Reserved.
% SPDX-License-Identifier: BSD-3-clause

lastwarn ('') ;
index = dimacs10 ;
[~,list] = sort (index.nnz) ;
if (nargin > 0)
    if (isscalar (arg) && arg < 0)
        list = list (1:(-arg)) ;
    else
        list = arg ;
    end