Add further assertion, and a comment
Add further assertion, and a comment

jonludlam/planex,euanh/planex-cleanhistory,euanh/planex-cleanhistory,simonjbeaumont/planex,jonludlam/planex,djs55/planex,simonjbeaumont/planex,simonjbeaumont/planex,djs55/planex,djs55/planex,jonludlam/planex,euanh/planex-cleanhistory