throw new UnsupportedOperationException();
  }

  /**
   * Not supported. <b>You are attempting to create a map that may contain a non-{@code Comparable}
   * key.</b> Proper calls will resolve to the version in {@code ImmutableSortedMap}, not this dummy
   * version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass a key of type {@code Comparable} to use {@link

    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. <b>You are attempting to create a map that may contain a non-{@code Comparable}
   * key.</b> Proper calls will resolve to the version in {@code ImmutableSortedMap}, not this dummy
   * version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass a key of type {@code Comparable} to use {@link

   */
  interface Trusted<V extends @Nullable Object> extends ListenableFuture<V> {}

  /**
   * A less abstract subclass of AbstractFuture. This can be used to optimize setFuture by ensuring
   * that {@link #get} calls exactly the implementation of {@link AbstractFuture#get}.
   */
  abstract static class TrustedFuture<V extends @Nullable Object> extends AbstractFuture<V>
      implements Trusted<V> {
    @CanIgnoreReturnValue

  }

  private static final int DISTINCT_CHARS = Character.MAX_VALUE - Character.MIN_VALUE + 1;

  /**
   * This is the actual implementation of {@link #precomputed}, but we bounce calls through a method
   * on {@link Platform} so that we can have different behavior in GWT.
   *
   * <p>This implementation tries to be smart in a number of ways. It recognizes cases where the

     */
    @CheckForNull
    V get();

    /** Returns the entry which contains this {@link WeakValueReference}. */
    E getEntry();

    /** Unsets the referenced value. Subsequent calls to {@link #get} will return {@code null}. */
    void clear();

    /**
     * Returns a freshly created {@link WeakValueReference} for the given {@code entry} (and on the

 * ListenableFuture}</a>.
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, Function, Executor) Futures.transform}, but you will often
 * find it easier to use a framework. Frameworks automate the process, often adding features like

 *
 * <p>If {@link #expireAfterWrite expireAfterWrite} or {@link #expireAfterAccess expireAfterAccess}
 * is requested entries may be evicted on each cache modification, on occasional cache accesses, or
 * on calls to {@link Cache#cleanUp}. Expired entries may be counted by {@link Cache#size}, but will
 * never be visible to read or write operations.
 *
 * <p>If {@link #weakKeys weakKeys}, {@link #weakValues weakValues}, or {@link #softValues

  }

  private static final int DISTINCT_CHARS = Character.MAX_VALUE - Character.MIN_VALUE + 1;

  /**
   * This is the actual implementation of {@link #precomputed}, but we bounce calls through a method
   * on {@link Platform} so that we can have different behavior in GWT.
   *
   * <p>This implementation tries to be smart in a number of ways. It recognizes cases where the

      return uncheckedCastNullableTToT(peekedElement);
    }
  }

  /**
   * Returns a {@code PeekingIterator} backed by the given iterator.
   *
   * <p>Calls to the {@code peek} method with no intervening calls to {@code next} do not affect the
   * iteration, and hence return the same object each time. A subsequent call to {@code next} is
   * guaranteed to return the same object again. For example:
   *

      return uncheckedCastNullableTToT(peekedElement);
    }
  }

  /**
   * Returns a {@code PeekingIterator} backed by the given iterator.
   *
   * <p>Calls to the {@code peek} method with no intervening calls to {@code next} do not affect the
   * iteration, and hence return the same object each time. A subsequent call to {@code next} is
   * guaranteed to return the same object again. For example:
   *