Trk::InverseMultiMap< OrigMap, CmpT > Node1 Trk::InverseMultiMap < OrigMap, CmpT > Node2 std::multimap< OrigMap ::mapped_type, OrigMap ::key_type, std::less< typename OrigMap::mapped _type >, SG::ArenaPoolSTLAllocator < std::pair< const OrigMap::mapped _type, OrigMap::key_type > > > + keys + elements Node2->Node1