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: get_subjroot.m
    path of file: ./repos/bspm/thirdparty/spm12/toolbox/marsbar-0.44/examples/batch
    
    the code of the file until where you have to start completion: function subjroot = get_subjroot()
% FORMAT subjroot = get_subjroot()
%
% Gets the root path for the example data.
% Looks first for an environment variable, if not defined, uses GUI
subjroot = getenv('MARSBAR_EG_DATAPATH');

    
function subjroot = get_subjroot()
% FORMAT subjroot = get_subjroot()
%
% Gets the root path for the example data.
% Looks first for an environment variable, if not defined, uses GUI
subjroot = getenv('MARSBAR_EG_DATAPATH');
% Otherwise fetch via the GUI
if isempty(subjroot)
    subjroot = spm_get(-1, '', 'Root directory of example data');
end