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: mvpcaveragerGUI.m
    path of file: ./repos/erplab/GUIs
    
    the code of the file until where you have to start completion: %
% Author: Aaron Matthew Simmons & Steven Luck
% Center for Mind and Brain
% University of California, Davis,
% Davis, CA
% 2009

%b8d3721ed219e65100184c6b95db209bb8d3721ed219e65100184c6b95db209b
%
% ERPLAB Toolbox
% Copyright Â© 2007 The Regents of the University of California
% Created by Javier Lopez-Calderon and Steven Luck
% Center for Mind and Brain, University of California, Davis,
% javlopez@ucdavis.edu, sjluck@ucdavis.edu
%
% This program is free software: you can redistribut
    
function checkbox_SEM_Callback(hObject, eventdata, handles)
% hObject    handle to checkbox_SEM (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of checkbox_SEM


% --- Executes on button press in pushbutton_addmvpcset.
function pushbutton_addmvpcset_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton_addmvpcset (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
[mvpcfname, mvpcpathname] = uigetfile({  '*.mvpc','Multivariate Pattern Classification files (*.mvpc)'; ...
        '*.mat','Matlab (*.mat)'; ...
        '*.*',  'All Files (*.*)'}, ...
        'Select an edited file', ...
        'MultiSelect', 'on');

if isequal(mvpcfname,0)
        disp('User selected Cancel')
        return
else
        if ~iscell(mvpcfname)
                mvpcfname = {mvpcfname};
        end