* already a {@code FluentIterable}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Collection#stream} if {@code iterable} is a {@link
   * Collection}; {@link Streams#stream(Iterable)} otherwise.
   */
  public static <E extends @Nullable Object> FluentIterable<E> from(final Iterable<E> iterable) {
    return (iterable instanceof FluentIterable)
        ? (FluentIterable<E>) iterable

   *
   * @deprecated instances of {@code FluentIterable} don't need to be converted to {@code
   *     FluentIterable}
   */
  @Deprecated
  @InlineMe(
      replacement = "checkNotNull(iterable)",
      staticImports = {"com.google.common.base.Preconditions.checkNotNull"})
  public static <E extends @Nullable Object> FluentIterable<E> from(FluentIterable<E> iterable) {
    return checkNotNull(iterable);
  }

  /**