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: test_tutorial_spikefield20130308.m
    path of file: ./repos/fieldtrip/test
    
    the code of the file until where you have to start completion: function failed_tutorial_spikefield20130308

% MEM 1gb
% WALLTIME 00:10:00
% DEPENDENCY
% DATA public

    
function failed_tutorial_spikefield20130308

% MEM 1gb
% WALLTIME 00:10:00
% DEPENDENCY
% DATA public

% Preprocessing
% The data for this tutorial can be downloaded on ftp://ftp.fieldtriptoolbox.org/pub/fieldtrip/tutorial/spikefield/p029_sort_final_01.nex. Make sure you add the main Fieldtrip directory to your path and run ft_defaults. We first read in the spike data by ft_read_spike and select the following channels for analysis from the spike structure using ft_spike_select by

filenex = dccnpath('/home/common/matlab/fieldtrip/data/ftp/tutorial/spikefield/p029_sort_final_01.nex');
spike  = ft_read_spike(filenex);

cfg              = [];
cfg.spikechannel = {'sig002a_wf', 'sig003a_wf'};
spike  = ft_spike_select(cfg, spike);

% giving a spike structure
%
% spike =
%
%         label: {'sig002a_wf'  'sig003a_wf'}
%     timestamp: {[1x164456 int32]  [1x134803 int32]}
%      waveform: {[1x32x164456 double]  [1x32x134803 double]}
%          unit: {[1x164456 double]  [1x134803 double]}
%           hdr: [1x1 struct]
%        dimord: '{chan}_lead_time_spike'
%           cfg: [1x1 struct]
% For more information on the spike format see the spike tutorial. Briefly, the field spike.timestamps contains the times of spiking for every cell in the unit of the recording system (called 'timestamps').
%
% We then construct a cfg.trl matrix to preprocess the LFP data. In this case, the unit of cfg.trl should be samples (not timestamps, as with ft_spike_maketrials), by
%
% function trl = trialfun_stimon_samples(cfg)
% hdr   = ft_read_header(cfg.dataset);
% event = ft_read_event(cfg.dataset);
% correctresponse  = 10041;
% begintrial       = 10044;
% end