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: ft_trackusage.m
    path of file: ./repos/spm12/external/fieldtrip/utilities
    
    the code of the file until where you have to start completion: function ft_trackusage(event, varargin)

% FT_TRACKUSAGE tracks the usage of specific FieldTrip components using a central
% tracking server. This involves sending a small snippet of information to the
% server. Tracking is only used to gather data on the usage of the FieldTrip
% toolbox, to get information on the number of users and on the frequency of use
% of specific toolbox functions. This allows the toolbox developers to improve the
% FIeldTrip toolbox source code, documentation and to provide better support.
%
% This function will NOT upload any information about the data, nor about the
% configuration that you are using in your analyses.
%
% This function will NOT upload any identifying details about you. Your username
% and computer name are "salted" and subsequently converted with the MD5
% cryptographic hashing function into a unique identifier. Not knowing the salt,
% it is impossible to decode these MD5 hashes and recover the original
% identifiers.
%
% It is possible to disable the tracking for all functions by specifying
% the following
%   global ft_defaults
%   ft_default.trackusage = 'no'
%
% See the following online documentation for more information
%   http://en.wikipedia.org/wiki/MD5
%   http://en.wikipedia.org/wiki/Salt_(cryptography)

    
function ft_trackusage(event, varargin)

% FT_TRACKUSAGE tracks the usage of specific FieldTrip components using a central
% tracking server. This involves sending a small snippet of information to the
% server. Tracking is only used to gather data on the usage of the FieldTrip
% toolbox, to get information on the number of users and on the frequency of use
% of specific toolbox functions. This allows the toolbox developers to improve the
% FIeldTrip toolbox source code, documentation and to provide better support.
%
% This function will NOT upload any information about the data, nor about the
% configuration that you are using in your analyses.
%
% This function will NOT upload any identifying details about you. Your username
% and computer name are "salted" and subsequently converted with the MD5
% cryptographic hashing function into a unique identifier. Not knowing the salt,
% it is impossible to decode these MD5 hashes and recover the original
% identifiers.
%
% It is possible to disable the tracking for all functions by specifying
% the following
%   global ft_defaults
%   ft_default.trackusage = 'no'
%
% See the following online documentation for more information
%   http://en.wikipedia.org/wiki/MD5
%   http://en.wikipedia.org/wiki/Salt_(cryptography)
%   http://www.fieldtriptoolbox.org/faq/tracking
%
% See also FT_DEFAULTS

% Copyright (C) 2015, Robert oostenveld
%
% This file is part of FieldTrip, see http://www.ru.nl/donders/fieldtrip
% 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/>.
%
% $Id$

try
  
  global ft_default
  persistent initialized
  
  if isempty(initialized)
    initialized = false;
  end
  
  if nargin<1
    % there is nothing to track
    return
  end
  
  if ~strcmp(mfilename, 'ft_trackusage')
    % this function should not be used outside of the FieldTrip toolbox without updating the token (see below)
    return
  end
  
  if ~ft_platform_supports('rng')
    % this function should not (yet) be used on Octave
    return
  end
  
  %% The first part pertains to keeping the tracking settings consistent over multiple MATLAB sessions
  
  % This functionality overlaps in part with what normally would be done using
  % ft_defaults, but is replicated here to make the tracking independent from the path
  % settings in ft_defaults.
  
  % locate the file that contains the persistent FieldTrip preferences
  fieldtripprefs  = fullfile(prefdir, 'fieldtripprefs.mat');
  
  if ~isfield(ft_default, 'trackusage')
    % read options from the preferences file
    if exist(fieldtripprefs, 'file')
      prefs      = load(fieldtripprefs); % the file contains multiple fields
      ft_default = mergeconfig(ft_default, prefs);
    end