*   <li>Return a {@code ClosingFuture}. To turn a {@link ListenableFuture} into a {@code
   *       ClosingFuture} call {@link #from(ListenableFuture)}.
   *   <li>In case this step doesn't create new closeables, you can adapt an API that returns a
   *       {@link ListenableFuture} to return a {@code ClosingFuture} by wrapping it with a call to
   *       {@link #withoutCloser(AsyncFunction)}
   * </ul>
   *
   * <p>Example usage:
   *

        *   `CategoryEncoding` no longer supports `adapt`, `IntegerLookup` now
            supports equivalent functionality. `max_tokens` argument renamed to
            `num_tokens`.
        *   `Discretization` added `num_bins` argument for learning bins
            boundaries through calling `adapt` on a dataset. Renamed `bins`
            argument to `bin_boundaries` for specifying bins without `adapt`.
    *   Improvements to model saving/loading: