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: SONChanBytes.m
    path of file: ./repos/PsPM/src/Import/SON/SON32
    
    the code of the file until where you have to start completion: function [bytes]=SONChanBytes(fh, chan)
% SONCHANBYTES returns the number of bytes written, or buffered, on the 

    
function [bytes]=SONChanBytes(fh, chan)
% SONCHANBYTES returns the number of bytes written, or buffered, on the 
% specified channel
% BYTES=SONCHANBYTES(FH, CHAN)
%                     FH SON file handle
%                     CHAN Channel number 0 to SONMAXCHANS-1
% 
%
% Author:Malcolm Lidierth
% Matlab SON library:
% Copyright 2005 © King’s College London

if nargin ~= 2
    bytes=-1000;
    return;
end