Write test for no_backprop_mode
Write test for no_backprop_mode

kiyukuta/chainer,okuta/chainer,chainer/chainer,chainer/chainer,wkentaro/chainer,hvy/chainer,okuta/chainer,kashif/chainer,hvy/chainer,tkerola/chainer,ktnyt/chainer,delta2323/chainer,wkentaro/chainer,hvy/chainer,chainer/chainer,jnishi/chainer,cupy/cupy,jnishi/chainer,wkentaro/chainer,cupy/cupy,ktnyt/chainer,wkentaro/chainer,niboshi/chainer,keisuke-umezawa/chainer,aonotas/chainer,ysekky/chainer,rezoo/chainer,keisuke-umezawa/chainer,jnishi/chainer,chainer/chainer,niboshi/chainer,keisuke-umezawa/chainer,ktnyt/chainer,niboshi/chainer,anaruse/chainer,keisuke-umezawa/chainer,okuta/chainer,niboshi/chainer,ronekko/chainer,cupy/cupy,jnishi/chainer,ktnyt/chainer,cupy/cupy,hvy/chainer,pfnet/chainer,okuta/chainer