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: cat.m
    path of file: ./repos/fieldtrip/external/spm8/@file_array
    
    the code of the file until where you have to start completion: function o = cat(dr,varargin)
% Concatenate file_array objects.  The result is a non-simple object

    
function o = cat(dr,varargin)
% Concatenate file_array objects.  The result is a non-simple object
% that can no longer be reshaped.
% _______________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

%
% $Id$


if dr>32 || dr<0, error('Unknown command option.'); end