Topological (adiabatic) pumps are typical problems where the bulk-edge correspondence is justified. The Chern number of the bulk and the behavior of the edge states are linked intimately. As for most of the topological phases, bulk is hidden and the edges are the physical observables by experiments. The situation is different in the pump. Here the physics of the edges can not be accessible by any finite speed pump since thermalization of the gapless edge states is only realized after infinite time. Then the center of mass due to the bulk is the experimental observable. It is special. Although the local U(1) gauge invariance is important, any further symmetry is required. In this sense, bosonic/fermionic pumps, without any symmetry breaking, are generic. Look at our recent paper “Topological pump and bulk-edge-correspondence in an extended Bose-Hubbard model” by Yoshihito Kuno and Yasuhiro Hatsugai, accepted for publication in Phys. Rev. B on 9 September 2021　and published on 29 September 2021. See also arXiv:2107.09498.