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: pad.m
    path of file: ./repos/spm12/external/fieldtrip/compat/matlablt2016b
    
    the code of the file until where you have to start completion: function [varargout] = pad(varargin)

    
function [varargout] = pad(varargin)

% PAD adds leading or trailing characters, such as spaces, to the left or
% right of an existing string.
%
% This is a compatibility function that should only be added to the path on
% MATLAB versions prior to R2016b.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% see https://github.com/fieldtrip/fieldtrip/issues/899

alternatives = which(mfilename, '-all');
if ~iscell(alternatives)
  % this is needed for octave, see https://github.com/fieldtrip/fieldtrip/pull/1171
  alternatives = {alternatives};
end