(function(){describe('Array extensions',function(){describe('first',function(){returnit('returns the first item',function(){vararr;arr=[0,1,2,3,4,5];returnexpect(arr.first()).toBe(0);});});describe('last',function(){returnit('returns the last item',function(){vararr;arr=[0,1,2,3,4,5];returnexpect(arr.last()).toBe(5);});});});