michael@0: function popper(a) {
michael@0:   return a.pop();
michael@0: }
michael@0: 
michael@0: function foo(x) {
michael@0:   for (var i = 0; i < 10; i++) {
michael@0:     var q = popper(x);
michael@0:     if (i < 5)
michael@0:       assertEq(q, 5 - i);
michael@0:     else
michael@0:       assertEq(q, undefined);
michael@0:   }
michael@0:   return q;
michael@0: }
michael@0: 
michael@0: var q = foo([1,2,3,4,5]);
michael@0: assertEq(q, undefined);