sort for doctest
sort for doctest

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