def down_block(ch, x):
    with tf.name_scope('down_resnet'):
        s = down(ch, x)
        r = convr(ch, s)
        return conv(ch, r, s)
def down_block(ch, x):
    with tf.name_scope('down_resnet'):
        s = down(ch, x)
        r = convr(ch, s)
        return conv(ch, r, s)