Replace tf.{data.experimental,contrib.data}.unbatch() with Dataset.unbatch().
" # Map ASCII chars to int64 indexes using the vocab\n",
" dataset.map(to_ids)\n",
" # Split into individual chars\n",
- " .apply(tf.data.experimental.unbatch())\n",
+ " .unbatch()\n",
" # Form example sequences of SEQ_LENGTH +1\n",
" .batch(SEQ_LENGTH + 1, drop_remainder=True)\n",
" # Shuffle and form minibatches\n",
