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: mvnormpdfln.m
    path of file: ./repos/lrslibrary/libs/+lightspeed
    
    the code of the file until where you have to start completion: function p = mvnormpdfln(x, m, S, V)
% MVNORMPDFLN    log of multivariate normal density.
%   See MVNORMPDF for argument description.

log2pi = 1.83787706640935;
[d, n] = size(x);
if nargin == 1
  dx = x;

    
function p = mvnormpdfln(x, m, S, V)
% MVNORMPDFLN    log of multivariate normal density.
%   See MVNORMPDF for argument description.

log2pi = 1.83787706640935;
[d, n] = size(x);
if nargin == 1
  dx = x;
elseif isempty(m)
  dx = x;
else
  % m specified
  sz = size(m);
  if sz(1) ~= d
    error('rows(m) ~= rows(x)')
  end