extracted from #5386
extracted from #5386

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