check edges while reading graph
check edges while reading graph

NicolasSchnitzler/dtk,d-tk/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,NicolasSchnitzler/dtk,rdebroiz/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,rdebroiz/dtk,d-tk/dtk,NicolasSchnitzler/dtk,rdebroiz/dtk