import tensorflow as tf

            pred_scores = policy['model']((c, ei, ev, v, tf.reduce_sum(n_cs, keepdims=True), tf.reduce_sum(n_vs, keepdims=True)), tf.convert_to_tensor(False))

            # filter candidate variables
            pred_scores = tf.expand_dims(tf.gather(tf.squeeze(pred_scores, 0), cands), 0)

        elif policy['type'] == 'ml-competitor':
