import tensorflow as tf

    def _initialize_weights(self):
        with tf.name_scope('parameters'):
            self.w0 = tf.Variable(tf.random_normal([28 * 28, 512]))
            self.b0 = tf.Variable(tf.zeros([512]))
            self.w1 = tf.Variable(tf.random_normal([512, 10]))
            self.b1 = tf.Variable(tf.zeros([10]))

    def _build_model(self, x, y):
        w0 = self.w0.read_value()
        b0 = self.b0.read_value()
