Note. Based on recent correspondence with the Whizard authors, it is suspected that any W mass 
dependence of the cross-section at ILC energies is much smaller than illustrated in the plots on mainly 
slides 12-20 (but also visible in slides 8-11).  This seems to have to do with Whizard using the on-shell 
mass scheme that defines the weak mixing angle in terms of mW and mZ rather than using other schemes 
that set the couplings to values consistent with experimentally measured sin^2{theta}_eff values.