import tensorflow as tf

              tf.reshape(detections['rotations_3d'][i], [3, 3]),
              1) for i in range(num_boxes)], axis=0)
          rotations_y = tf.reshape(rotations_y, [-1, 1])
          labeled_boxes = tf.concat([sample['translations_3d'],
                                     sample['sizes_3d'],
                                     rotations_y], axis=1)
