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: update_ess.m
    path of file: ./repos/bnt/BNT/CPDs/@tabular_CPD
    
    the code of the file until where you have to start completion: function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
% UPDATE_ESS Update the Expected Sufficient Statistics of a tabular node.
% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)

dom = fmarginal.domain;

if all(hidden_bitv(dom))
  CPD = update_ess_simple(CPD, fmarginal.T);

    
function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
% UPDATE_ESS Update the Expected Sufficient Statistics of a tabular node.
% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)

dom = fmarginal.domain;

if all(hidden_bitv(dom))
  CPD = update_ess_simple(CPD, fmarginal.T);
  %fullm = add_ev_to_dmarginal(fmarginal, evidence, ns);
  %assert(approxeq(fullm.T(:), fmarginal.T(:)))
else
  fullm = add_ev_to_dmarginal(fmarginal, evidence, ns);
  CPD = update_ess_simple(CPD, fullm.T);
end