refactoring for addContentRange.
refactoring for addContentRange.

frontrowed/wai,yesodweb/wai,dylex/wai,beni55/wai,beni55/wai,AndrewRademacher/wai,sol/wai,iquiw/wai,awpr/wai,jberryman/wai,frontrowed/wai,sordina/wai,utdemir/wai,awpr/wai,utdemir/wai,dylex/wai,coypoop/wai,sordina/wai,iquiw/wai,ygale/wai,erikd/wai,creichert/wai,awpr/wai,tolysz/wai,creichert/wai,soenkehahn/wai,dylex/wai,soenkehahn/wai,mfine/wai,jberryman/wai,erikd/wai,AndrewRademacher/wai,sol/wai,dylex/wai,frontrowed/wai,frontrowed/wai,sordina/wai,AndrewRademacher/wai,soenkehahn/wai,urbanslug/wai,utdemir/wai,tolysz/wai,coypoop/wai,beni55/wai,tolysz/wai,mfine/wai,kazu-yamamoto/wai,urbanslug/wai,urbanslug/wai,rgrinberg/wai,sordina/wai,rgrinberg/wai,mfine/wai,ygale/wai,ygale/wai,coypoop/wai,soenkehahn/wai,jberryman/wai,erikd/wai,yesodweb/wai,iquiw/wai,coypoop/wai,utdemir/wai,beni55/wai,rgrinberg/wai,AndrewRademacher/wai,tolysz/wai,urbanslug/wai,mfine/wai,awpr/wai,jberryman/wai,rgrinberg/wai,ygale/wai,erikd/wai,kazu-yamamoto/wai,rgrinberg/wai,sol/wai,iquiw/wai