* objects per entry.  Instead we use an open-addressed hash table.  This design is basically
   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *

   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it
   * won't compile on Java 7, while if we don't include the method then the compiler will complain
   * that an abstract method is unimplemented. So instead we use a dynamic proxy to get an

          && knownOrder == KnownOrder.UNKNOWN_ORDER) {
        /*
         * We already know the iterator is an Iterator<E>, and now we know that
         * we called next(), so the returned element must be of type E.
         */
        @SuppressWarnings("unchecked")
        E targetReturnValueFromNext = (E) targetReturnValue;
        /*
         * We have an Iterator<E> and want to cast it to

     * always call succeedsIn*() to initialize them immediately thereafter.
     *
     * The exception is the *InValueSet fields of multimapHeaderEntry, which are never set. (That
     * works out fine as long as we continue to be careful not to try to delete them or iterate
     * past them.)
     *

    expectContents();
  }

  // retainAll(null)

  /*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

      this.durationNanos = durationNanos;
    }

    @Override
    @ParametricNullness
    public T get() {
      // Another variant of Double Checked Locking.
      //
      // We use two volatile reads. We could reduce this to one by
      // putting our fields into a holder class, but (at least on x86)
      // the extra memory consumption and indirection are more
      // expensive than the extra volatile reads.

    assertEquals(1 << 29, ImmutableSet.chooseTableSize((1 << 29) * 3 / 5));

    // Now we hit the cap
    assertEquals(1 << 30, ImmutableSet.chooseTableSize(1 << 29));
    assertEquals(1 << 30, ImmutableSet.chooseTableSize((1 << 30) - 1));

    // Now we've gone too far
    assertThrows(IllegalArgumentException.class, () -> ImmutableSet.chooseTableSize(1 << 30));
  }

    void calculateNextPermutation() {
      int j = findNextJ();
      if (j == -1) {
        nextPermutation = null;
        return;
      }
      /*
       * requireNonNull is safe because we don't clear nextPermutation until we're done calling this
       * method.
       */
      requireNonNull(nextPermutation);

      int l = findNextL(j);
      Collections.swap(nextPermutation, j, l);

     * TODO(cpovirk): use Object[] instead of E[] in the mainline? (The backport is different and
     * doesn't need this suppression, but we keep it to minimize diffs.) Generally be more clear
     * about when we have an Object[] vs. a Comparable[] or other array type in internalArray? If we
     * used Object[], we might be able to optimize toArray() to use clone() sometimes. (See
     * cl/592273615 and cl/592273683.)
     */

   * find it when available. When this is null, use the slow way.
   */
  @J2ktIncompatible
  @GwtIncompatible // java.lang.reflect
  @CheckForNull
  private static final Method getStackTraceElementMethod = (jla == null) ? null : getGetMethod();

  /**
   * The "getStackTraceDepth" method, only available on some JDKs so we use reflection to find it