ARCH-COMP19 category report: hybrid systems with piecewise constant dynamics by Frehse, G, Abate, A, Adzkiya, D, Becchi, A, Bu, L, Cimatti, A, Giacobbe, M, Griggio, A, Mover, S, Syifa'ul Mufid, M, Riouak, I, Tonetta, S, Zaffanella, E