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: VBA_spm_get_defaults.m
    path of file: ./repos/VBA-toolbox/thrid-party/spm
    
    the code of the file until where you have to start completion: function varargout = VBA_spm_get_defaults(defstr, varargin)
% Get/set the defaults values associated with an identifier
% FORMAT defaults = spm_get_defaults
% Return the global "defaults" variable defined in spm_defaults.m.
%
% FORMAT defval = spm_get_defaults(defstr)
% Return the defaults value associated with identifier "defstr". 
% Currently, this is a '.' subscript reference into the global  
% "defaults" variable defined in spm_defaults.m.
%

    
function varargout = VBA_spm_get_defaults(defstr, varargin)
% Get/set the defaults values associated with an identifier
% FORMAT defaults = spm_get_defaults
% Return the global "defaults" variable defined in spm_defaults.m.
%
% FORMAT defval = spm_get_defaults(defstr)
% Return the defaults value associated with identifier "defstr". 
% Currently, this is a '.' subscript reference into the global  
% "defaults" variable defined in spm_defaults.m.
%
% FORMAT spm_get_defaults(defstr, defval)
% Set the defaults value associated with identifier "defstr" to defval.
% The new defaults value applies immediately to:
% * new modules in batch jobs
% * modules in batch jobs that have not been saved yet
% This value will not be saved for future sessions of SPM. To make
% persistent changes, see help section in spm_defaults.m.
%__________________________________________________________________________
% Copyright (C) 2008-2014 Wellcome Trust Centre for Neuroimaging

% Volkmar Glauche
% $Id: spm_get_defaults.m 6157 2014-09-05 18:17:54Z guillaume $


global defaults;

if isempty(defaults)
    spm_defaults;
end