Erratum: "Investigating the impact of patient arm position in an MR‐linac on liver SBRT treatment plans" [Med. Phys. Vol 46, 5144‐5151 (2019)]. Issue 3 (11th February 2020) - van den Wollenberg, Wouter; de Ruiter, Peter; Nowee, Marlies E.; Jansen, Edwin P.M.; Sonke, Jan‐Jakob; Fast, Martin F.