[cernRoot]Get graphs from TMultiGraph

    int ngr = mg[4]->GetListOfGraphs()->GetSize();
    TList * gr_list = mg[0]->GetListOfGraphs();
    TGraph * gr0 = (TGraph *)gr_list->First();
    TGraph * gr1 = (TGraph *)gr0->Clone();
    TGraph * gr0 = (TGraph *)gr_list->After(gr0);
    TGraph * gr2 = (TGraph *)gr0->Clone();
    TGraph * gr0 = (TGraph *)gr_list->After(gr0);
    TGraph * gr3 = (TGraph *)gr0->Clone();