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_run_tissue_volumes.m
    path of file: ./repos/spm/config
    
    the code of the file until where you have to start completion: function out = spm_run_tissue_volumes(cmd, job)
% SPM job execution function for Tissue Volumes
%
% See also: spm_cfg_tissue_volumes, spm_summarise
%__________________________________________________________________________

% Ged Ridgway
% Copyright (C) 2013-2022 Wellcome Centre for Human Neuroimaging


switch lower(cmd)
    
    %======================================================================
    case 'exec'

    
function out = spm_run_tissue_volumes(cmd, job)
% SPM job execution function for Tissue Volumes
%
% See also: spm_cfg_tissue_volumes, spm_summarise
%__________________________________________________________________________

% Ged Ridgway
% Copyright (C) 2013-2022 Wellcome Centre for Human Neuroimaging


switch lower(cmd)
    
    %======================================================================
    case 'exec'
        
        % input parameters
        mat = job.matfiles;
        T   = job.tmax;
        msk = char(job.mask);
        outf = job.outf;
        if isempty(msk)
            msk = 'all';
        end