Remove unused import
Remove unused import

kashif/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,kikusu/chainer,niboshi/chainer,niboshi/chainer,wkentaro/chainer,jnishi/chainer,truongdq/chainer,cupy/cupy,AlpacaDB/chainer,aonotas/chainer,t-abe/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,okuta/chainer,tkerola/chainer,kikusu/chainer,cemoody/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,AlpacaDB/chainer,ktnyt/chainer,pfnet/chainer,benob/chainer,truongdq/chainer,cupy/cupy,okuta/chainer,t-abe/chainer,muupan/chainer,hvy/chainer,ktnyt/chainer,jnishi/chainer,ysekky/chainer,jnishi/chainer,hvy/chainer,ronekko/chainer,kiyukuta/chainer,tscohen/chainer,wkentaro/chainer,chainer/chainer,chainer/chainer,delta2323/chainer,okuta/chainer,chainer/chainer,anaruse/chainer,niboshi/chainer,cupy/cupy,wkentaro/chainer,cupy/cupy,sinhrks/chainer,rezoo/chainer,sinhrks/chainer,okuta/chainer,chainer/chainer,ktnyt/chainer,jnishi/chainer,wkentaro/chainer,benob/chainer,muupan/chainer,ktnyt/chainer