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: read_neuralynx_nev.m
    path of file: ./repos/spm12/external/fieldtrip/fileio/private
    
    the code of the file until where you have to start completion: function [nev] = read_neuralynx_nev(filename, varargin)

% READ_NEURALYNX_NEV reads the event information from the *.nev file in a
% Neuralynx dataset directory
%
% Use as
%   nev = read_neuralynx_hdr(datadir, ...)
%   nev = read_neuralynx_hdr(eventfile, ...)
%
% Optional input arguments should be specified in key-value pairs and may include
%   implementation  should be 1, 2 or 3 (default = 3)
%   value           number or list of numbers
%   mintimestamp    number
%   maxtimestamp    number
%   minnumber       number
%   maxnumber       number
%
% The output structure contains all events and timestamps.

% Copyright (C) 2005, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip is distributed in the hope that it will be useful,
%    but WITHOUT ANY WARRANTY; without even the implied warranty of
%    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%    GNU General Public License for more details.
%
%    You should have received a copy of the GNU General Public License
%    along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.
%
% $Id$

% get the optional input arguments
flt_value        = ft_getopt(varargin, 'value');

    
function [nev] = read_neuralynx_nev(filename, varargin)

% READ_NEURALYNX_NEV reads the event information from the *.nev file in a
% Neuralynx dataset directory
%
% Use as
%   nev = read_neuralynx_hdr(datadir, ...)
%   nev = read_neuralynx_hdr(eventfile, ...)
%
% Optional input arguments should be specified in key-value pairs and may include
%   implementation  should be 1, 2 or 3 (default = 3)
%   value           number or list of numbers
%   mintimestamp    number
%   maxtimestamp    number
%   minnumber       number
%   maxnumber       number
%
% The output structure contains all events and timestamps.

% Copyright (C) 2005, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip is distributed in the hope that it will be useful,
%    but WITHOUT ANY WARRANTY; without even the implied warranty of
%    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%    GNU General Public License for more details.
%
%    You should have received a copy of the GNU General Public License
%    along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.
%
% $Id$

% get the optional input arguments
flt_value        = ft_getopt(varargin, 'value');
flt_mintimestamp = ft_getopt(varargin, 'mintimestamp');
flt_maxtimestamp = ft_getopt(varargin, 'maxtimestamp');
flt_minnumber    = ft_getopt(varargin, 'minnumber');
flt_maxnumber    = ft_getopt(varargin, 'maxnumber');
implementation   = ft_getopt(varargin, 'implementation', 3);

if ft_filetype(filename, 'neuralynx_ds')
  % replace the directory name by the filename
  if     exist(fullfile(filename, 'Events.Nev'))
    filename = fullfile(filename, 'Events.Nev');
  elseif exist(fullfile(filename, 'Events.nev'))
    filename = fullfile(filename, 'Events.nev');
  elseif exist(fullfile(filename, 'events.Nev'))
    filename = fullfile(filename, 'events.Nev');
  elseif exist(fullfile(filename, 'events.nev'))
    filename = fullfile(filename, 'events.nev');
  end