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_read_data.m
    path of file: ./repos/PsPM/src/Import/fieldtrip/fileio
    
    the code of the file until where you have to start completion: function [dat] = ft_read_data(filename, varargin)

% FT_READ_DATA reads electrophysiological data from a variety of EEG, MEG and LFP
% files and represents it in a common data-independent format. The supported formats
% are listed in the accompanying FT_READ_HEADER function.
%
% Use as
%   dat = ft_read_data(filename, ...)
%
% Additional options should be specified in key-value pairs and can be
%   'header'         header structure, see FT_READ_HEADER
%   'beg
    
function supplied by Gijs van Elswijk
    %
    % CED ADC is done in sequence, thus the analog channels
    % do not share the same time axis. This is _ignored_ here.
    %
    % Set the READ_CED_SON parameter 'readtimestamps' to
    % 'yes' to get time axis for each data channel returned.
    % This time information can be used to do
    % a temporal realignment of the data.
    tmp = read_ced_son(filename,'readdata','yes',...
      'begsample',begsample,...
      'endsample',endsample,...
      'channels',chanindx);
    dat = cell2mat(tmp.data');
    
  case 'combined_ds'
    dat = read_combined_ds(filename, hdr, begsample, end