Add comments that data is shared, not copied
Add comments that data is shared, not copied

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