Use assert
Use assert

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