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: dss2ss.m
    path of file: ./repos/lc_toolbox/Util
    
    the code of the file until where you have to start completion: % This file is part of LCToolbox.
% (c) Copyright 2018 - MECO Research Team, KU Leuven. 
%
% LCToolbox is free software: you can redistribute it and/or modify
% it under the terms of the GNU Less
    
function [sysout,is_pss,r] = dss2ss(sysin)
%DSS2SS Converts a descriptor state space model into a proper state space
%model.
%   Converts a descriptor state space model into a proper state space
%   model. States that are unnecessary are removed. This does not include a
%   possible cancellation of poles and zeros.
%   In case the underlying model is improper, the the output state
%   space model is still in the descriptor form.
%   input:
%   ipss = (im)proper state space model to be converted
%   output:
%   pss = (im)proper output state space model
%   is_pss = 0 if the input system is improper, 1 if the input is proper and
%   the output therefore is in a regular state space form
%   r = amount of removed states

flag = false;
if isa(sysin,'AbstractDSSmod')
    ipss = std(sysin);
    flag = true;
else
    ipss = sysin;
end