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: simpleCache.m
    path of file: ./repos/toolbox/matlab
    
    the code of the file until where you have to start completion: function varargout = simpleCache( op, cache, varargin )
% A simple cache that can be used to store results of computations.

    
function varargout = simpleCache( op, cache, varargin )
% A simple cache that can be used to store results of computations.
%
% Can save and retrieve arbitrary values using a vector (includnig char
% vectors) as a key. Especially useful if a function must perform heavy
% computation but is often called with the same inputs (for which it will
% give the same outputs).  Note that the current implementation does a
% linear search for the key (a more refined implementation would use a hash
% table), so it is not meant for large scale usage.
%
% To use inside a function, make the cache persistent:
%  persistent cache; if( isempty(cache) ) cache=simpleCache('init'); end