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: logsumexp.m
    path of file: ./repos/lrslibrary/libs/+lightspeed
    
    the code of the file until where you have to start completion: function s = logsumexp(a, dim)
% Returns log(sum(exp(a),dim)) while avoiding numerical underflow.
% Default is dim = 1 (columns).

    
function s = logsumexp(a, dim)
% Returns log(sum(exp(a),dim)) while avoiding numerical underflow.
% Default is dim = 1 (columns).
% logsumexp(a, 2) will sum across rows instead of columns.
% Unlike matlab's "sum", it will not switch the summing direction
% if you provide a row vector.

% Written by Tom Minka
% (c) Microsoft Corporation. All rights reserved.

if nargin < 2
  dim = 1;
end