import tensorflow as tf


        with tf.name_scope('validate'):
            x, y = self._build_data_pipeline()
            y_hat, loss = self._build_validation_model(x, y)

            with tf.control_dependencies([update_op]):
                return tf.print('expect', loss, y, y_hat, summarize=50)


class DataOwner:

    BATCH_SIZE = 30
