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_cfg_bbox.m
    path of file: ./repos/ExploreASL/External/SPMmodified/config
    
    the code of the file until where you have to start completion: function bbox = spm_cfg_bbox
% SPM Configuration file for Get Bounding Box
%__________________________________________________________________________
% Copyright (C) 2013 Wellcome Trust Centre for Neuroimaging

% Ged Ridgway
% $Id: spm_cfg_bbox.m 5301 2013-03-05 18:33:39Z ged $

img             = cfg_files;
img.tag         = 'image';

    
function bbox = spm_cfg_bbox
% SPM Configuration file for Get Bounding Box
%__________________________________________________________________________
% Copyright (C) 2013 Wellcome Trust Centre for Neuroimaging

% Ged Ridgway
% $Id: spm_cfg_bbox.m 5301 2013-03-05 18:33:39Z ged $

img             = cfg_files;
img.tag         = 'image';
img.name        = 'Image';
img.help        = {'Image for which to determine bounding box.'};
img.filter      = 'image';
img.ufilter     = '.*';
img.num         = [1 1];

fov             = cfg_const;
fov.tag         = 'fov';
fov.name        = 'Field of view';
fov.help        = {'Bounding box is for entire field of view of image.'};
fov.val         = {'fv'};

thr             = cfg_entry;
thr.tag         = 'threshold';
thr.name        = 'Threshold';
thr.help        = {'Bounding box is for set of voxels above this value.'};
thr.strtype     = 'r';
thr.num         = [1 1];

stv             = cfg_branch;
stv.tag         = 'stv';
stv.name        = 'Supra-threshold voxels';
stv.help        = {'Bounding box is for voxels over specified threshold.'};
stv.val         = {thr};

bbdef           = cfg_choice;
bbdef.tag       = 'bbdef';
bbdef.name      = 'Bounding box definition';
bbdef.help      = {
    ['Bounding box for field of view (using only header information) ' ...
    'or for the set of voxels over a specified threshold.']};
bbdef.values    = {fov stv};
bbdef.val       = {fov};

bbox            = cfg_exbranch;
bbox.tag        = 'bbox';
bbox.name       = 'Get Bounding Box';
bbox.val        = {img bbdef};
bbox.help       = {
    ['Determine the bounding box of an image, i.e. the [2 x 3] array ' ...
    'of the minimum and maximum X, Y, and Z coordinates (in mm), ']
    'BB = [min_X min_Y min_Z'
    '      max_X max_Y max_Z]'};
bbox.prog       = @(job) bbox_run(job);
bbox.vout       = @(job) bbox_vout(job);


%--------------------------------------------------------------------------
function out = bbox_run(job)
try
    thr = job.bbdef.stv.threshold;
catch
    thr = 'fv';
end