if( m_existingMetaDataChan.insert(mcChannelNumber).second )
{
  xAOD::TruthMetaData* md = new xAOD::TruthMetaData();
  m_tmd->push_back( md );

  auto weightNameMap = genEvt->m_weights.m_names;

  std::vector<std::string> orderedWeightNameVec( weightNameMap.size() );

  for (auto& weightNameMap: entry) {
    orderedWeightNameVec.push_back(entry.first);
  }

  //The map from the HepMC record pairs the weight names with a corresponding index,
  //it is not guaranteed that the indices are ascending when iterating over the map
  std::sort(orderedWeightNameVec.begin(), orderedWeightNameVec.end(),
  [&](std::string i, std::string j){return weightNameMap.at(i) < weightNameMap.at(j);});

  md->setMcChannelNumber(mcChannelNumber);
  md->setWeightNames( std::move(orderedWeightNameVec) );
}