import tensorflow as tf

            self.conv3 = self._residual_block('conv3_2', self.conv3, 128)
            _debug(self.conv3)

        with tf.variable_scope('conv4_x'):
            self.conv4 = self._residual_block('conv4_1', self.conv3, 256, pool_first=True, strides=2)
            _debug(self.conv4)
