SG::initParams< T, clear, no_ctor, no_dtor > Node1 SG::initParams< T, clear, no_ctor, no _dtor >   + initParams() + params() + operator ArenaAllocatorBase ::Params() Node2 SG::ArenaAllocatorBase ::initParams< T, false, false, false > - m_nblock - m_name + initParams() + params() + operator Params() Node2->Node1