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_eeg_regressors_movement_ctf.m
    path of file: ./repos/spm12
    
    the code of the file until where you have to start completion: function res = spm_eeg_regressors_movement_ctf(S)
% Generate movement regressors for CTF MEG data
% S                     - input structure
% fields of S:
%    S.D                - M/EEG object
%
%    Additional parameters can be defined specific for each plugin
% Output:
%  res -
%   If no input is provided the plugin returns a cfg branch for itself
%
%   If input is provided the plugin returns
%______________________________________________________________________________________
% Copyright (C) 2014 Wellcome Trust Centre for Neuroimaging

% Vladimir Litvak

SVNrev = '$Rev: 6186 $';

if nargin == 0
    
    Dmov        = cfg_files;
    Dmov.tag    = 'Dmov';
    Dmov.name   = 'Movement dataset name';
    Dmov.filter = 'mat';
    Dmov.num    = [1 1];
    Dmov.help   = {'Select the M/EEG mat file containing continuous head localisation data.',...

    
function res = spm_eeg_regressors_movement_ctf(S)
% Generate movement regressors for CTF MEG data
% S                     - input structure
% fields of S:
%    S.D                - M/EEG object
%
%    Additional parameters can be defined specific for each plugin
% Output:
%  res -
%   If no input is provided the plugin returns a cfg branch for itself
%
%   If input is provided the plugin returns
%______________________________________________________________________________________
% Copyright (C) 2014 Wellcome Trust Centre for Neuroimaging

% Vladimir Litvak

SVNrev = '$Rev: 6186 $';

if nargin == 0
    
    Dmov        = cfg_files;
    Dmov.tag    = 'Dmov';
    Dmov.name   = 'Movement dataset name';
    Dmov.filter = 'mat';
    Dmov.num    = [1 1];
    Dmov.help   = {'Select the M/EEG mat file containing continuous head localisation data.',...
        'This might or might not be the same as the dataset being analysed.'};
    
    
    movement_ctf = cfg_branch;
    movement_ctf.tag = 'movement_ctf';
    movement_ctf.name = 'CTF head movements';
    movement_ctf.val = {Dmov};
    
    res = movement_ctf;
    
    return
end