import tensorflow as tf

        batch1 = tf.gather(batch, tf.random.shuffle(index))
        batch2 = tf.gather(batch, tf.random.shuffle(index))
        pred1 = tf.slice(batch1, [0, 0], [num_sam, 1])
        pred2 = tf.slice(batch2, [0, 0], [num_sam, 1])
