Raise error if stretch or interval inputs are not class instances
Raise error if stretch or interval inputs are not class instances

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