import tensorflow as tf

                        gru_fw, outputs[-1] * mask_fw, seq_len, initial_state=init_fw, dtype=tf.float32)
                with tf.variable_scope("bw_{}".format(layer)):
                    inputs_bw = tf.reverse_sequence(
                        outputs[-1] * mask_bw, seq_lengths=seq_len, seq_dim=1, batch_dim=0)
                    out_bw, _ = tf.nn.dynamic_rnn(
                        gru_bw, inputs_bw, seq_len, initial_state=init_bw, dtype=tf.float32)
                    out_bw = tf.reverse_sequence(
                        out_bw, seq_lengths=seq_len, seq_dim=1, batch_dim=0)
