Dbg::HistTemp Node1 Dbg::HistTemp + HistTemp() + HistTemp() Node2 ActsUtils::StatHist + m_xmin + m_scale + StatHist() + StatHist() + setBinning() + createEmptyClone() + add() + reset() + operator+=() + lowerEdge() + histogramToString() Node2->Node1 +ATLAS_THREAD_SAFE Node3 ActsUtils::Stat + m_n + m_sum + m_sum2 + m_min + m_max + add() + n() + min() + max() + mean() + rms2() + rms() + reset() + operator+=() Node3->Node2 Node4 std::vector< unsigned int > + elements Node4->Node2 +m_histogram