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_check_installation.m
    path of file: ./repos/spm
    
    the code of the file until where you have to start completion: function varargout = spm_check_installation(action)

    
function varargout = spm_check_installation(action)
% Check SPM installation
% FORMAT spm_check_installation('basic')
% Perform a superficial check of SPM installation [default].
%
% FORMAT spm_check_installation('full')
% Perform an in-depth diagnostic of SPM installation.
%
% FORMAT rev = spm_check_installation('rev')
% Return a lower bound of SPM SVN Revision number.
% 
% FORMAT spm_check_installation('build')
% Build signature of SPM distribution as used by 'full' option.
% (for developers)
%__________________________________________________________________________

% Guillaume Flandin
% Copyright (C) 2009-2023 Wellcome Centre for Human Neuroimaging


if isdeployed, return; end