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_eeg_inv_mix.m
    path of file: ./repos/spm12/config
    
    the code of the file until where you have to start completion: function inv_mix = spm_cfg_eeg_inv_mix
% Configuration file for merging (using a new inversion) a number of
% imaging source inversion reconstructions
%__________________________________________________________________________
% Copyright (C) 2010 Wellcome Trust Centre for Neuroimaging

% Gareth Barnes
% $Id: spm_cfg_eeg_inv_mix.m 5924 2014-03-19 14:59:12Z gareth $

D = cfg_files;
D.tag = 'D';
D.name = 'M/EEG datasets';
D.filter = 'mat';
D.num = [1 Inf];
D.help = {'Select the M/EEG mat files or .mat files containing inverses'};

val = cfg_entry;
val.tag = 'val';
val.name = 'Inversion index';
val.strtype = 'n';
val.help = {'Index of the cell in D.inv (same for all files) where the forward model can be found and the results will be stored.'};
val.val = {1};

prefix = cfg_entry;
prefix.tag = 'prefix';
prefix.name = 'Merged file prefix';
prefix.strtype = 's';
prefix.val={'merged'};
prefix.help = {'Prefix for the new filename that will contain the merged inversion results'};

    
function inv_mix = spm_cfg_eeg_inv_mix
% Configuration file for merging (using a new inversion) a number of
% imaging source inversion reconstructions
%__________________________________________________________________________
% Copyright (C) 2010 Wellcome Trust Centre for Neuroimaging

% Gareth Barnes
% $Id: spm_cfg_eeg_inv_mix.m 5924 2014-03-19 14:59:12Z gareth $

D = cfg_files;
D.tag = 'D';
D.name = 'M/EEG datasets';
D.filter = 'mat';
D.num = [1 Inf];
D.help = {'Select the M/EEG mat files or .mat files containing inverses'};

val = cfg_entry;
val.tag = 'val';
val.name = 'Inversion index';
val.strtype = 'n';
val.help = {'Index of the cell in D.inv (same for all files) where the forward model can be found and the results will be stored.'};
val.val = {1};

prefix = cfg_entry;
prefix.tag = 'prefix';
prefix.name = 'Merged file prefix';
prefix.strtype = 's';
prefix.val={'merged'};
prefix.help = {'Prefix for the new filename that will contain the merged inversion results'};





inv_mix = cfg_exbranch;
inv_mix.tag = 'inv_mix';
inv_mix.name = 'Merge source estimates from multiple inversions';
inv_mix.val = {D, val,prefix};
inv_mix.help = {'To merge different source level variance estimates based on the same data'};
inv_mix.prog = @run_inv_mix;
inv_mix.vout = @vout_inv_mix;
inv_mix.modality = {'MEG'};

function  out = run_inv_mix(job)


inverse = [];
if numel(job.D)<1,
    error('Need to add a number of files to combine');
end