ActsTrk::HgtdBlueprintNodeBuilder Node1 ActsTrk::HgtdBlueprintNode Builder - m_hgtdMgr - m_elementStore + initialize() + buildBlueprintNode() - buildHgtdBlueprintNode() - addHgtdLayers() Node2 extends< AthAlgTool, IBlueprintNodeBuilder >     Node2->Node1