H5Utils::Merger Node1 H5Utils::Merger # m_mergeAxis # m_chunkSize # m_requireSameFormat # m_bufferSize # m_measureBufferInRows + Merger() + ~Merger() + merge() + merge() + createFrom() + createFrom() + flush() Node2 std::unique_ptr< H5Utils ::hist::HistogramMerger >   + operator->() Node2->Node1 #m_histMerger Node3 H5Utils::hist::Histogram Merger   + ~HistogramMerger() + add() + write() - make() Node3->Node2 +ptr Node4 std::map< std::string, std::unique_ptr< H5Utils ::hist::IHistogram > >     Node4->Node3 -m_hists Node5 std::string     Node5->Node4 +keys Node6 std::basic_string< Char >     Node6->Node5 Node7 std::unique_ptr< H5Utils ::hist::IHistogram >   + operator->() Node7->Node4 +elements Node8 H5Utils::hist::IHistogram   + ~IHistogram() + add() + write() Node8->Node7 +ptr