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: script_faster_rcnn_demo.m
    path of file: ./repos/faster_rcnn/experiments
    
    the code of the file until where you have to start completion: function script_faster_rcnn_demo()
close all;
clc;
clear mex;
clear is_valid_handle; % to clear init_key
run(fullfile(fileparts(fileparts(mfilename('fullpath'))), 'startup'));
%% -------------------- CONFIG --------------------
opts.caffe_version          = 'caffe_faster_rcnn';
opts.gpu_id                 = auto_select_gpu;
active_caffe_mex(opts.gpu_id, opts.caffe_version);

opts.per_nms_topN           = 6000;
opts.nms_overlap_thres      = 0.7;
opts.after_nms_topN         = 300;
opts.use_gpu                = true;

opts.test_scales            = 600;

%% -------------------- INIT_MODEL --------------------
model_dir                   = fullfile(pwd, 'output', 
    
function proposal_detection_model = load_proposal_detection_model(model_dir)
    ld                          = load(fullfile(model_dir, 'model'));
    proposal_detection_model    = ld.proposal_detection_model;
    clear ld;
    
    proposal_detection_model.proposal_net_def ...
                                = fullfile(model_dir, proposal_detection_model.proposal_net_def);
    proposal_detection_model.proposal_net ...
                                = fullfile(model_dir, proposal_detection_model.proposal_net);
    proposal_detection_model.detection_net_def ...
                                = fullfile(model_dir, proposal_detection_model.detection_net_def);
    proposal_detection_model.detection_net ...
                                = fullfile(model_dir, proposal_detection_model.detection_net);
    
end