*   `tf.data.Options` were previously immutable and can now be overridden.
*   `tf.data.Dataset.from_generator` now supports Ragged and Sparse tensors with
    a new `output_signature` argument, which allows `from_generator` to produce
    any type describable by a `tf.TypeSpec`.
*   `tf.data.experimental.AUTOTUNE` is now available in the core API as
    `tf.data.AUTOTUNE`.