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: jtree_dbn_inf_engine.m
    path of file: ./repos/bnt/BNT/inference/dynamic/@jtree_dbn_inf_engine/Old
    
    the code of the file until where you have to start completion: function engine = jtree_dbn_inf_engine(bnet, varargin)
% JTREE_DBN_INF_ENGINE Junction tree inference algorithm for DBNs.

ss = length(bnet.intra);

onodes = [];

if nargin >= 2
  args = varargin;

    
function engine = jtree_dbn_inf_engine(bnet, varargin)
% JTREE_DBN_INF_ENGINE Junction tree inference algorithm for DBNs.

ss = length(bnet.intra);

onodes = [];

if nargin >= 2
  args = varargin;
  nargs = length(args);
  for i=1:2:nargs
    switch args{i},
     case 'observed', onodes = args{i+1};
    end