document some assumptions; remove unused variable
document some assumptions; remove unused variable

no functional changes

tony-o/rakudo,labster/rakudo,nbrown/rakudo,azawawi/rakudo,Leont/rakudo,labster/rakudo,ugexe/rakudo,awwaiid/rakudo,LLFourn/rakudo,rjbs/rakudo,jonathanstowe/rakudo,paultcochrane/rakudo,azawawi/rakudo,salortiz/rakudo,salortiz/rakudo,tony-o/rakudo,b2gills/rakudo,b2gills/rakudo,labster/rakudo,awwaiid/rakudo,pmurias/rakudo,pmurias/rakudo,rakudo/rakudo,raydiak/rakudo,tbrowder/rakudo,nbrown/rakudo,zostay/rakudo,dwarring/rakudo,cygx/rakudo,Gnouc/rakudo,cygx/rakudo,ab5tract/rakudo,sjn/rakudo,sjn/rakudo,paultcochrane/rakudo,pmurias/rakudo,skids/rakudo,dankogai/rakudo,usev6/rakudo,ungrim97/rakudo,teodozjan/rakudo,labster/rakudo,ungrim97/rakudo,ugexe/rakudo,nbrown/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,skids/rakudo,ungrim97/rakudo,niner/rakudo,nunorc/rakudo,Leont/rakudo,rakudo/rakudo,paultcochrane/rakudo,nunorc/rakudo,ab5tract/rakudo,niner/rakudo,lucasbuchala/rakudo,laben/rakudo,laben/rakudo,LLFourn/rakudo,usev6/rakudo,raydiak/rakudo,b2gills/rakudo,retupmoca/rakudo,dwarring/rakudo,awwaiid/rakudo,zhuomingliang/rakudo,zostay/rakudo,Gnouc/rakudo,dankogai/rakudo,zhuomingliang/rakudo,zhuomingliang/rakudo,rakudo/rakudo,azawawi/rakudo,lucasbuchala/rakudo,teodozjan/rakudo,niner/rakudo,jonathanstowe/rakudo,rakudo/rakudo,awwaiid/rakudo,usev6/rakudo,samcv/rakudo,laben/rakudo,ugexe/rakudo,sergot/rakudo,lucasbuchala/rakudo,awwaiid/rakudo,tony-o/rakudo,softmoth/rakudo,tony-o/deb-rakudodaily,retupmoca/rakudo,b2gills/rakudo,raydiak/rakudo,dankogai/rakudo,tony-o/deb-rakudodaily,samcv/rakudo,tbrowder/rakudo,salortiz/rakudo,Gnouc/rakudo,azawawi/rakudo,dwarring/rakudo,MasterDuke17/rakudo,salortiz/rakudo,rjbs/rakudo,teodozjan/rakudo,cognominal/rakudo,dankogai/rakudo,MasterDuke17/rakudo,tony-o/deb-rakudodaily,usev6/rakudo,softmoth/rakudo,rjbs/rakudo,Leont/rakudo,cognominal/rakudo,jonathanstowe/rakudo,pmurias/rakudo,tony-o/deb-rakudodaily,cygx/rakudo,paultcochrane/rakudo,skids/rakudo,softmoth/rakudo,nbrown/rakudo,zostay/rakudo,retupmoca/rakudo,Gnouc/rakudo,MasterDuke17/rakudo,tony-o/deb-rakudodaily,sjn/rakudo,jonathanstowe/rakudo,zostay/rakudo,tony-o/rakudo,ungrim97/rakudo,dwarring/rakudo,ugexe/rakudo,cognominal/rakudo,ab5tract/rakudo,b2gills/rakudo,cognominal/rakudo,lucasbuchala/rakudo,sjn/rakudo,usev6/rakudo,Leont/rakudo,skids/rakudo,LLFourn/rakudo,cognominal/rakudo,tony-o/deb-rakudodaily,rakudo/rakudo,tbrowder/rakudo,tony-o/rakudo,skids/rakudo,raydiak/rakudo,softmoth/rakudo,ab5tract/rakudo,MasterDuke17/rakudo,azawawi/rakudo,zhuomingliang/rakudo,rakudo/rakudo,sergot/rakudo,ungrim97/rakudo,Gnouc/rakudo,salortiz/rakudo,ab5tract/rakudo,tbrowder/rakudo,Gnouc/rakudo,cygx/rakudo,lucasbuchala/rakudo,nbrown/rakudo,retupmoca/rakudo,LLFourn/rakudo,sergot/rakudo,LLFourn/rakudo,nunorc/rakudo,nbrown/rakudo,niner/rakudo,ugexe/rakudo,tony-o/rakudo,labster/rakudo,samcv/rakudo,sergot/rakudo,samcv/rakudo,nunorc/rakudo,dankogai/rakudo,sjn/rakudo,softmoth/rakudo,cygx/rakudo,salortiz/rakudo,labster/rakudo,tony-o/deb-rakudodaily,samcv/rakudo,laben/rakudo,jonathanstowe/rakudo,paultcochrane/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,teodozjan/rakudo