TIDA::Histogram2D< T, U > Node1 TIDA::Histogram2D< T, U >   + Fill() + Fill() + operator->() + HistogramBase() + HistogramBase() Node2 TIDA::HistogramBase - m_monTool - m_name - m_varname - m_initialised + HistogramBase() + HistogramBase() + name() + varname() + initialised() + monTool() Node2->Node1