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_statfun_diff.m
    path of file: ./repos/fieldtrip/statfun
    
    the code of the file until where you have to start completion: function [s, cfg] = ft_statfun_diff(cfg, dat, design)

% FT_STATFUN_DIFF demonstrates how to compute the difference of the mean in two
% conditions. Although it can be used for statistical testing, it will have rather
% limited sensitivity and is not really suited for inferential testing.
%
% This function serves as an example for a statfun. You can use such a function with
% the statistical framework in FieldTrip using FT_TIMELOCKSTATISTICS,
% FT_FREQSTATISTICS or FT_SOURCESTATISTICS to perform a statistical test, without

    
function [s, cfg] = ft_statfun_diff(cfg, dat, design)

% FT_STATFUN_DIFF demonstrates how to compute the difference of the mean in two
% conditions. Although it can be used for statistical testing, it will have rather
% limited sensitivity and is not really suited for inferential testing.
%
% This function serves as an example for a statfun. You can use such a function with
% the statistical framework in FieldTrip using FT_TIMELOCKSTATISTICS,
% FT_FREQSTATISTICS or FT_SOURCESTATISTICS to perform a statistical test, without
% having to worry about the representation of the data.
%
% Use this function by calling the high-level statistic functions as
%   [stat] = ft_freqstatistics(cfg, freq1, freq2, ...)
% with the following configuration option:
%   cfg.statistic = 'ft_statfun_diff_itc'
%
% The experimental design is specified as:
%   cfg.ivar  = independ