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: mdm_philips_fexi_prot2xps.m
    path of file: ./repos/md-dmri/mdm
    
    the code of the file until where you have to start completion: function xps = mdm_philips_fexi_prot2xps(prot_fn, xps)
% function xps = mdm_philips_fexi_prot2xps(prot_fn, xps)

    
function xps = mdm_philips_fexi_prot2xps(prot_fn, xps)
% function xps = mdm_philips_fexi_prot2xps(prot_fn, xps)
%
% Parse a Philips protocol text file in prot_fn, and store it in an xps
%
% The protocol file must have been generated with the FEXI patch
%
% An xps must be provided and some fields must have been filled in 
% (see this file for details)


% associate tm so different s_ind's
if (~isfield(xps, 's_ind')), error('xps.s_ind required'); end