Import Foundation if not testing
Import Foundation if not testing

Fix an issue that `NSSet` not being recognized.
dougbeal/Cartography,kliu/Cartography,xBrux/Cartography,rankun203/Cartography,petester42/Cartography,tonyli508/Cartography-IOS7,ppamorim/Cartography,zilaiyedaren/Cartography,u10int/Cartography,ernestopino/Cartography,PiersonBro/Cartography,sai43/Cartography,tonyli508/Cartography,gaurav1981/Cartography,bestwpw/Cartography,ArthurKK/Cartography,noluyo/Cartography,TimothyChilvers/Cartography,ken0nek/Cartography,brunov0id/Cartography,bzmario/Cartography,TimothyChilvers/Cartography,sai43/Cartography,KyoheiG3/Cartography,LiuDeng/Cartography,zilaiyedaren/Cartography,linchanlau/Cartography,cnbin/Cartography,kliu/Cartography,vinod1988/Cartography,ernestopino/Cartography,lixiaohu1990/Cartography,noluyo/Cartography,eeschimosu/Cartography,dougbeal/Cartography,fullstackclub/Cartography,u10int/Cartography,bestwpw/Cartography,seyton/Cartography,tonyli508/Cartography,petester42/Cartography,cogddo/Cartography,iosyoujian/Cartography,eeschimosu/Cartography,ArthurKK/Cartography,iosyoujian/Cartography,cnbin/Cartography,KyoheiG3/Cartography,jessesquires/Cartography,ppamorim/Cartography,alvivi/Cartography,vinod1988/Cartography,xBrux/Cartography,msdgwzhy6/Cartography,Khan/Cartography,tonyli508/Cartography-IOS7,Khan/Cartography,gaurav1981/Cartography,seyton/Cartography,msdgwzhy6/Cartography,linchanlau/Cartography,ken0nek/Cartography,jessesquires/Cartography,alvivi/Cartography,bzmario/Cartography,cogddo/Cartography,fullstackclub/Cartography,brunov0id/Cartography,lixiaohu1990/Cartography,PiersonBro/Cartography,rankun203/Cartography,LiuDeng/Cartography