*/
  public final Optional<@NonNull E> firstMatch(Predicate<? super E> predicate) {
    // Unsafe, but we can't do much about it now.
    return Iterables.<@NonNull E>tryFind((Iterable<@NonNull E>) getDelegate(), predicate);
  }

  /**
   * Returns a fluent iterable that applies {@code function} to each element of this fluent
   * iterable.
   *

   * <p>If your index may associate multiple values with each key, use {@link #index(Function)
   * index}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code
   * stream.collect(ImmutableMap.toImmutableMap(keyFunction, v -> v))}.
   *
   * @param keyFunction the function used to produce the key for each value
   * @return a map mapping the result of evaluating the function {@code keyFunction} on each value

 * }
 * }
 *
 * ... produces output such as:
 *
 * {@snippet :
 * Zachary: [Taylor]
 * John: [Adams, Adams, Tyler, Kennedy]  // Remember, Quincy!
 * George: [Washington, Bush, Bush]
 * Grover: [Cleveland, Cleveland]        // Two, non-consecutive terms, rep'ing NJ!
 * ...
 * }
 *
 * <h3>Views</h3>
 *
 * <p>Much of the power of the multimap API comes from the <i>view collections</i> it provides.

      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

      b) in the case of each subsequent Contributor:

         i) changes to the Program, and

         ii) additions to the Program;

where such changes and/or additions to the Program originate from and are
distributed by that particular Contributor. A Contribution 'originates' from
a Contributor if it was added to the Program by such Contributor itself or

      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

  b) in the case of each subsequent Contributor:
     i) changes to the Program, and
     ii) additions to the Program;
  where such changes and/or additions to the Program originate from
  and are Distributed by that particular Contributor. A Contribution
  "originates" from a Contributor if it was added to the Program by
  such Contributor itself or anyone acting on such Contributor's behalf.