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: mgaRoot.m
    path of file: ./repos/CellExplorer/calc_CellMetrics
    
    the code of the file until where you have to start completion: function path = mgaRoot
%MGAROOT Returns root path for mga toolbox folder

% store path persistently for repeat calls

    
function path = mgaRoot
%MGAROOT Returns root path for mga toolbox folder

% store path persistently for repeat calls
persistent r
if isempty(r)
    r = fileparts(mfilename('fullpath'));
end