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: link.m
    path of file: ./repos/spm12/@meeg
    
    the code of the file until where you have to start completion: function this = link(this, fnamedat, dtype, slope, offset)
% Links the object to data file (only if exists)
% FORMAT this = link(this) 
%   Will try to find the datafile based on fname and path     
% FORMAT this = link(this, fnamedat) 
%   Will find the datafile using the provided name and path
% FORMAT this = link(this, fnamedat, dtype, slope, offset)
%   Additional parameters for non-float data files
% _________________________________________________________________________
% Copyright (C) 2011 Wellcome Trust Centre for Neuroimaging


    
function this = link(this, fnamedat, dtype, slope, offset)
% Links the object to data file (only if exists)
% FORMAT this = link(this) 
%   Will try to find the datafile based on fname and path     
% FORMAT this = link(this, fnamedat) 
%   Will find the datafile using the provided name and path
% FORMAT this = link(this, fnamedat, dtype, slope, offset)
%   Additional parameters for non-float data files
% _________________________________________________________________________
% Copyright (C) 2011 Wellcome Trust Centre for Neuroimaging

% Vladimir Litvak
% $Id: link.m 6437 2015-05-14 12:27:21Z vladimir $

if isempty(this)
   error('All header dimensions should be >0');
end