Advancing urban transitions and transformations research by Torrens, J, Westman, L, Wolfram, M, Broto, VC, Barnes, J, Egermann, M, Ehnert, F, Frantzeskaki, N, Fratini, CF, Håkansson, I, Hölscher, K, Huang, P, Raven, R, Sattlegger, A, Schmidt-Thomé, K, Smeds, E, Vogel, N, Wangel, J, von Wirth, T