import tensorflow as tf

            ul_u_eval_train = placeholder_like(ul_images_eval_train, "ul_u_eval_train")
            ul_u_eval_test =  placeholder_like(images_eval_test, "ul_u_eval_test")

        with tf.device(FLAGS.device):
            lr = tf.placeholder(tf.float32, shape=[], name="learning_rate")
            mom = tf.placeholder(tf.float32, shape=[], name="momentum")
