BackendConfig.get_array to accept None
BackendConfig.get_array to accept None

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