ActsTrk::DevicePixelMeasurement< BASE > Node1 ActsTrk::DevicePixelMeasurement < BASE >   + identifier() + identifier() + local_position() + local_position() + local_variance() + local_variance() + global_position() + global_position() + module_id_hash() + module_id_hash() + operator==() + operator<=>() * identifier() * identifier() * local_position() * local_position() * local_variance() * local_variance() * global_position() * global_position() * module_id_hash() * module_id_hash() * operator==() * operator<=>() Node2 BASE     Node2->Node1