raise error if iterator repeats and n == 0
raise error if iterator repeats and n == 0

ktnyt/chainer,ktnyt/chainer,okuta/chainer,tkerola/chainer,jnishi/chainer,wkentaro/chainer,chainer/chainer,wkentaro/chainer,ktnyt/chainer,niboshi/chainer,jnishi/chainer,pfnet/chainer,niboshi/chainer,jnishi/chainer,niboshi/chainer,chainer/chainer,wkentaro/chainer,hvy/chainer,okuta/chainer,keisuke-umezawa/chainer,okuta/chainer,keisuke-umezawa/chainer,jnishi/chainer,hvy/chainer,keisuke-umezawa/chainer,ktnyt/chainer,hvy/chainer,chainer/chainer,wkentaro/chainer,niboshi/chainer,chainer/chainer,okuta/chainer,keisuke-umezawa/chainer,hvy/chainer