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: aamod_slicetiming.m
    path of file: ./repos/automaticanalysis/aa_modules
    
    the code of the file until where you have to start completion: % AA module - slice timing
% [aap,resp]=aamod_slicetiming(aap,task,subj,sess)
% Corrects the slice time difference in 2D EPI sequences
% Do not use on 3D EPI (it will not work!)
% Rhodri Cusack MRC CBU 2004 based on original by Matthew Brett
% Batching slice timing in SPM5
% Tibor Auer MRC CBU Cambridge 2012-2013

function [aap,resp]=aamod_slicetiming(aap,task,subj,sess)
resp='';

switch task
    case 'domain'
        resp='session';   % this module needs to be run once per session
    case 'description'
        resp='SPM8 slice timing';
    case 'summary'
        resp=sprintf('Perform slice timing, with TR %f and time to acquire single slice %f\n',aap.tasklist.currenttask.settings.TRs, aap.tasklist.currenttask.settin
    
function [aap,resp]=aamod_slicetiming(aap,task,subj,sess)
resp='';

switch task
    case 'domain'
        resp='session';   % this module needs to be run once per session
    case 'description'
        resp='SPM8 slice timing';
    case 'summary'
        resp=sprintf('Perform slice timing, with TR %f and time to acquire single slice %f\n',aap.tasklist.currenttask.settings.TRs, aap.tasklist.currenttask.settings.slicetime);
    case 'report'
    case 'doit'
        
        % get the subdirectories in the main directory
        dirn = aas_getsesspath(aap,subj,sess);
        
        % get files in this directory
        imgs=aas_getimages_bystream(aap,subj,sess,'epi');
        
        % get information from first file
        first_img = deblank(imgs(1,:));
        DICOMHEADERS = load(aas_getimages_bystream(aap,subj,sess,'epi_dicom_header'));
        hdr = DICOMHEADERS.DICOMHEADERS{1};
        V = spm_vol(first_img);
        if isfield(aap.options, 'NIFTI4D') && aap.options.NIFTI4D % 4D support [TA]
            V = V(1);
        end