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: mio_pad.m
    path of file: ./repos/md-dmri/mio
    
    the code of the file until where you have to start completion: function I = mio_pad(I, pad_xyz)

    
function I = mio_pad(I, pad_xyz)
% function I = mio_pad(I, pad_xyz)
%
% Adds zero around 'I' according to the three numbers in 'pad_xyz', 
% which may be negative (this leads to trimming instead)

if (all(pad_xyz == 0)), return; end