HistValFunctions::TH2_FieldsAccess Node1 HistValFunctions::TH2 _FieldsAccess + access_fTsumwy() + access_fTsumwy2() + access_fTsumwxy() + access_fScalefactor() + access_fTsumwy() + access_fTsumwy2() + access_fTsumwxy() + access_fScalefactor() Node2 TH2 + Fill() + Fill() + Fill() + Fill() + Fill() Node2->Node1