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: spm_dcm_contrasts.m
    path of file: ./repos/spm12
    
    the code of the file until where you have to start completion: function con = spm_dcm_contrasts(DCM,D)
% Make contrast vector for a DCM
% FORMAT con = spm_dcm_contrasts(DCM,D)
%
% DCM    - DCM structure or its filename

    
function con = spm_dcm_contrasts(DCM,D)
% Make contrast vector for a DCM
% FORMAT con = spm_dcm_contrasts(DCM,D)
%
% DCM    - DCM structure or its filename
% D      - 'A','B' or 'C' i.e. connectivity matrix of interest
%
% con    - column vector specifying contrast weights
%__________________________________________________________________________
% Copyright (C) 2002-2014 Wellcome Trust Centre for Neuroimaging
 
% Will Penny
% $Id: spm_dcm_contrasts.m 6031 2014-06-02 12:49:52Z guillaume $
 

%-Load DCM if necessary
%--------------------------------------------------------------------------
if ~isstruct(DCM)
    load(DCM);
end