Add documenation for getVssForStream methods

        return streamState != null ? streamState.getIndex(device) : -1;

    }

    /**

     * Returns the {@link VolumeStreamState} corresponding to the passed stream type. This can be

     * {@code null} since not all possible stream types have a valid {@link VolumeStreamState} (e.g.

     * {@link AudioSystem#STREAM_BLUETOOTH_SCO}) is deprecated and will return a {@code null} stream

     * state).

     *

     * @param stream the stream type for querying the stream state

     *

     * @return the {@link VolumeStreamState} corresponding to the passed stream type or {@code null}

     */

    @Nullable

    /*package*/ VolumeStreamState getVssForStream(int stream) {

        return mStreamStates.get(stream);

    }

    /**

     * Returns the {@link VolumeStreamState} corresponding to the passed stream type. In case

     * there is no associated stream state for the given stream type we return the default stream

     * state for {@link AudioSystem#STREAM_MUSIC} (or throw an {@link IllegalArgumentException} in

     * the ramp up phase of the replaceStreamBtSco flag to ensure that this case will never happen).

     *

     * @param stream the stream type for querying the stream state

     *

     * @return the {@link VolumeStreamState} corresponding to the passed stream type

     */

    @NonNull

    /*package*/ VolumeStreamState getVssForStreamOrDefault(int stream) {

        VolumeStreamState streamState = mStreamStates.get(stream);