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: cnn_setup_data_voc07.m
    path of file: ./repos/refinenet/libs/matconvnet/examples/fast_rcnn/datasets
    
    the code of the file until where you have to start completion: function imdb = cnn_setup_data_voc07(varargin)
%CNN_VOC07_SETUP_DATA  Download Initialize PASCAL VOC 2007 data
%

    
function imdb = cnn_setup_data_voc07(varargin)
%CNN_VOC07_SETUP_DATA  Download Initialize PASCAL VOC 2007 data
%
% Copyright (C) 2016 Hakan Bilen.
% All rights reserved.
%
% This file is part of the VLFeat library and is made available under
% the terms of the BSD license (see the COPYING file).

opts.dataDir = fullfile('data') ;
opts.useTest = true ;
opts.useDifficult = true ;
opts.addFlipped = true ;
opts = vl_argparse(opts, varargin) ;

% -------------------------------------------------------------------------
%                                                  Load categories metadata
% -------------------------------------------------------------------------

if ~exist(opts.dataDir, 'dir')
  mkdir(opts.dataDir) ;
end