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: cat_get_defaults.m
    path of file: ./repos/ExploreASL/External/SPMmodified/toolbox/cat12
    
    the code of the file until where you have to start completion: function varargout = cat_get_defaults(defstr, varargin)
% Get/set the defaults values associated with an identifier
% FORMAT defval = cat_get_defaults(defstr)
% Return the defaults value associated with identifier "defstr". 

    
function varargout = cat_get_defaults(defstr, varargin)
% Get/set the defaults values associated with an identifier
% FORMAT defval = cat_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 cat_get_defaults(defstr, defval)
% Sets the cat value associated with identifier "defstr". The new
% cat 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, edit cat_defaults.m.
%
% FORMAT cat_get_defaults(defstr, 'rmfield')
% Removes last field of defstr eg. defstr = 'opts.sopt.myfield' will remove 
% 'myfield'. 
%
% FORMAT cat_get_defaults(defstr, 'rmentry')
% Removes last field of defstr eg. defstr = 'opts.sopt.myfield' will remove 
% 'sopt' with all all subfield. 
%__________________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

% based on Volkmar Glauches version of
% spm_get_defaults
% $Id: cat_get_defaults.m 1562 2020-02-11 13:53:30Z dahnke $

global cat;
if isempty(cat)
    cat_defaults;
end