RootPlanarClusterWriter does not write barcodes properly to file

The barcodes of the particles are properly produced and handed over to the RootPlanarClusterWriter member variable m_t_barcode but it is not written properly to file. Since this bug only exists in this class but not in e.g. the RootParticleWriter, its origin could be in the different storage type. While the particles always have a single barcode the clusters store an std::vector<barcode_type>. The indication of the underlying data type of the barcode is provided to the TTree by the line m_outputTree->Branch("truth_barcode", &m_t_barcode, "truth_barcode/l"); with the /l indicating that the object is of type ULong64_t. However it looks like this only treats a single object but not a vector of objects correctly. Since I did not test it on multiple machines to see if this is an issue of my setup or not one should take a look whether this is a real bug issue.