code: def slice_hidden(self, x):
      
      x_sliced = tf.reshape(
          x, shape=[-1, self.hparams.num_blocks, self.hparams.block_dim])
      return x_sliced
docs: Slice encoder hidden state into block_dim.
  
      Args:
          x: Encoder hidden state of shape [-1, hidden_size].
  
      Returns:
          Sliced states of shape [-1, num_blocks, block_dim].