Trk::IVertexAnalyticSeedFinder Node1 Trk::IVertexAnalyticSeed Finder + DeclareInterfaceID() + findAnalyticSeed() Node2 Trk::IVertexSeedFinder + DeclareInterfaceID() + findSeed() + findSeed() + findSeed() + findSeed() + findMultiSeeds() + findMultiSeeds() Node2->Node1 Node3 IAlgTool Node3->Node2