if (child0 != nullptr && child1 != nullptr) {
                    // check for parent-child relations
                    auto pdg0 = child0->GetPdgCode();
                    auto pdg1 = child1->GetPdgCode();
                    std::cout << "First and last children of parent " << checkPdgSignal << " are PDG0: " << pdg0 << " PDG1: " << pdg1 << "\n";
                    if (std::abs(pdg0) == checkPdgDecay && std::abs(pdg1) == checkPdgDecay && pdg0 == -pdg1) {
nLeptonPairs++;
                    if (child0->getToBeDone() && child1->getToBeDone()) {
                        nLeptonPairsToBeDone++;
                    }
                    }