We want to thank the two anonymous reviewers and the guest editor of this issue for their thoughtful and highly constructive advice given to us during the revision stage; their careful reading and advice greatly improved this article. This study was supported by a grant to J. Mestre and M.A.M. from the National Science Foundation Division of Undergraduate Education, grant no. DUE-1630128, to the University of Illinois, Champaign–Urbana.