implementation tweaks suggestested by @mhvk
implementation tweaks suggestested by @mhvk

StuartLittlefair/astropy,saimn/astropy,saimn/astropy,stargaser/astropy,dhomeier/astropy,aleksandr-bakanov/astropy,astropy/astropy,DougBurke/astropy,kelle/astropy,aleksandr-bakanov/astropy,mhvk/astropy,kelle/astropy,kelle/astropy,MSeifert04/astropy,stargaser/astropy,mhvk/astropy,saimn/astropy,DougBurke/astropy,pllim/astropy,astropy/astropy,bsipocz/astropy,pllim/astropy,larrybradley/astropy,saimn/astropy,MSeifert04/astropy,dhomeier/astropy,lpsinger/astropy,dhomeier/astropy,bsipocz/astropy,DougBurke/astropy,funbaker/astropy,pllim/astropy,funbaker/astropy,AustereCuriosity/astropy,bsipocz/astropy,astropy/astropy,StuartLittlefair/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,AustereCuriosity/astropy,pllim/astropy,aleksandr-bakanov/astropy,mhvk/astropy,larrybradley/astropy,mhvk/astropy,kelle/astropy,larrybradley/astropy,dhomeier/astropy,kelle/astropy,bsipocz/astropy,pllim/astropy,funbaker/astropy,mhvk/astropy,lpsinger/astropy,MSeifert04/astropy,stargaser/astropy,StuartLittlefair/astropy,lpsinger/astropy,astropy/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,saimn/astropy,larrybradley/astropy,dhomeier/astropy,funbaker/astropy,larrybradley/astropy,DougBurke/astropy,StuartLittlefair/astropy,lpsinger/astropy,lpsinger/astropy,astropy/astropy,AustereCuriosity/astropy,MSeifert04/astropy,stargaser/astropy