1 hello
   2 hello
   3 hello
   4 TypeError:1:read property "foo" from undefined
   5 TypeError:1:read property "foo" from undefined
   6 TypeError:1:read property "foo" from undefined
   7 TypeError:1:read property "foo" from undefined
   8 TypeError:1:read property "foo" from undefined
   9 TypeError:1:read property "foo" from undefined